NPCs

Among the characters involved with the Left 4 Dead series, there are a number of Non-Playable Characters that help the Survivors along the way, or in some cases, hinder their progress. Often, they are either a roadblock forcing a Crescendo Event or they are a good Samaritan providing the Survivors with a ride to safety. Most of these characters become Infected (such as the CEDA Worker Infected), are killed (such as Annie and Jeff), can be presumed dead as they are never seen again (such as Louis' co-worker Ray), or continue to survive the apocalypse (such as Virgil and Whitaker).

In-Game characters
These characters are encountered within both the PC and Xbox 360 versions of the Left 4 Dead series.

The Church Guy
"Better safe than sorry...better safe than sorry..."

- The Church Guy

The Church Guy is a mentally unstable man who is never actually seen until he turns Infected, and can be found in chapter three of the Death Toll campaign, The Church. He is afraid of the Infection, locking himself in the safe room that the Survivors must get through. It is later revealed that he was bitten by a survivor who claimed to be immune, yet became an Infected; as a result, he suffers from extreme paranoia of Survivors, coupled with the growing insanity caused by Infection. After waiting for an hour, he assumes that he is immune. Ultimately, it turns out the Church Guy isn't immune after all; he will change into a Hunter, Smoker, or Boomer.

He repeatedly says "Better safe than sorry", and causes a Crescendo Event where he rings the church bell to attract a Horde to kill the Survivors, apparently viewing this as a way for them to "prove their immunity/humanity". After the event, the safe room door can be opened and a Special Infected will emerge, providing a conclusion to his change. The Infected he will change into can be foretold by listening to the Church Guy starting to growl (Hunter), cough (Smoker), or gurgle (Boomer) before the door is opened. After opening the door and ascending to the second floor of the safe room, the Survivors can see that the Church Guy has written his motto all over a wall, over 180 times.

His voice actor, Nathan Vetterlein, also voiced the Scout from Valve's Team Fortress 2.

The Survivor who infected him was a male, judging by the audio files. However, a corpse of a female slumped against the wall in the safe room can be seen; it does not appear to be a Common Infected, but a body that spawns to set the mood like the dead soldiers on the roof of Mercy Hospital.

Despite ongoing rumors and popular belief of a slim chance of it occurring, he will never turn into a Tank after the Crescendo Event. According to the left4dead/scripts/population.txt file, it appears that there is a 50% chance of a Boomer appearing, and 25% each of either a Smoker or a Hunter appearing. No mention of the Tank or the Witch are included in this file, making it clear that there is no chance of the Church Guy becoming a Tank unless there is a server-side mod in use. He will never transform into a Witch, as Witches are only created from women. Alteration of the population.txt file to force the Church Guy to transform into a Tank or a Witch can create very strange results, thus verifying the fact that the Church Guy will never spawn as a Tank.

The Church Guy's audio clips can be heard here.

Whitaker
"Now I've barricaded myself on the roof with ample provisions... but in my haste, I forgot cola!"

- Whitaker

Whitaker is a 60-year-old man who owns a gun store located in front of Liberty Mall in the Dead Center campaign. By the time the Survivors arrive at his gun store, he has already barricaded himself "on the roof" with large amounts of ammunition and provisions.

When the Survivors enter his store, he is contacted over an intercom and offers to clear a roadblock that is preventing The Survivors from reaching the mall on condition they go to the nearby Save 4 Less supermarket and fetch him a six-pack of Cola. A Crescendo Event is triggered when the Survivors enter the supermarket and set off the burglar alarm. Once the cola has been deposited in the delivery tray in his safe room door, Whitaker launches a missile at a flammable truck near the roadblock, destroying it and allowing the Survivors to continue to the mall.

Trivia

 * Some commentators believe Whitaker may have used a Rocket Launcher or Rocket Propelled Grenade because it has a different sound effect to the Grenade Launcher featured later in the game and its projectile trails a line of smoke to its target.
 * Originally, Whitaker was supposed to provide covering fire to the Survivors during their trip to and from the supermarket (a concept reprised in The Passing Finale).
 * The Fallen Survivor Uncommon Infected model uses an Infected version of his model.
 * Whitaker is very similar to the character Andy from the 2004 film Dawn of the Dead. They are both apocalypse survivors who own barricaded gun stores and stayed on the roof but lack 'important' supplies (food for Andy, Cola for Whitaker).
 * Whitaker is voiced by Dayton Callie.

Evacuation Personnel
During the finale of every campaign, other than Dead Center, The Passing and The Sacrifice, a Survivor in a vehicle must arrive to rescue the four main characters from their evacuation point. These Survivors are never seen and have no active or dynamic role in gameplay. These Survivors include the helicopter pilot from No Mercy, the boat drivers (John and Amanda Slater) from Death Toll, the C-130 pilot from Dead Air, and the APC driver from Blood Harvest. In all cases, players communicate with them via radio. In Blood Harvest, verbal exchanges between two military evacuation personnel are heard on the radio once the mic is keyed.

Each rescuer has separate motives for rescuing the Survivors:
 * The helicopter pilot in No Mercy can appear to be affiliated with either the military or CEDA with a role of evacuating civilians to an unknown safe zone. However, since he flies the News Chopper 5, it can equally be assumed he was simply a former news pilot evacuating civilians out of good will. If this is the case, he was part of a fairly large news network considering there are advertising posters for the helicopter in The Subway.
 * John and Amanda Slater (the boat pilots) are civilians hoping to gain additional firepower as they escape from Riverside.
 * The C-130 pilot appears to be stranded at the airport due to a lack of fuel and afraid to leave his plane and expose himself to the Infected. His voice actor is Gary Schwartz, who voiced the Heavy and Demoman in Team Fortress 2.
 * The APC driver in Blood Harvest, Lieutenant Mora, is a member of the U.S. military who was ordered to evacuate the Survivors to an unknown (but presumably the northern) safe zone. His voice actor is David Scully.
 * The helicopter pilot in Dark Carnival is never directly contacted, but is presumably looking for survivors for the same reasons as the helicopter pilot in No Mercy, with whom he shares the same character model.
 * Virgil is a boat owner who presumably picks up the Survivors out of a combination of kindness, potential loneliness, and expediency based on his need to get fuel from the mainland.
 * The military helicopter pilot in The Parish has been expressly tasked with orders to pick up the Survivors if they make it to his aircraft before the bridge is bombed and destroyed. He is never seen and he is separated from the passenger compartment of his helicopter by a rigid bulkhead.

News Chopper 5 Pilot
The Chopper pilot is seen in the intro video to Left 4 Dead, and in the start of No Mercy, he tells anyone who can hear him to proceed to Mercy Hospital where they can contact him with a radio and he will pick them up and bring them to an unknown location. During the rescue at the top of Mercy Hospital, he will engage in communication with the Survivors, where he will reveal he had an "incident", implying he attempted another rescue earlier but was attacked by the Infected.

Unfortunately for the Survivors who are rescued and taken to apparent safety, the pilot is infected, turns into an Infected mid-flight, and is shot by Zoey, forcing a crash landing. The Survivors being Carriers of infection may be the reason the News Chopper 5 pilot became an Infected as stated in The Sacrifice comic or he may have been infected during his street pickup as he stated in the Rooftop Finale.

Although his cap appears to have associations with the United States Marine Corps possibly showing a military background, his civilian clothing may also indicate he is currently not affiliated with them. The headphones he wears are Aero-X Orbital 2000's.

His voice actor is Dennis Bateman, who also voiced the Spy and Pyro in Team Fortress 2.

John and Amanda Slater
John Slater is contacted by radio at the end of the Death Toll campaign. He and his wife pick up the Survivors in their boat and get them away from Riverside. John Slater's motives are evidently those of self-interest and survival because he makes it clear that he is expressly interested in hearing from "anyone out there with firearms". This point is reinforced when, according to the comic, the Survivors were later thrown off the boat and left to die. The reason for this is unknown, but one conclusion is that the Slaters were only interested in expropriating The Survivors' weapons (but refer also to the following discussion).

In The Sacrifice campaign, Bill explains his desire to escape in a sailboat by arguing that he doesn't want to stop "every fifteen minutes" to refuel a motorized boat. This could allude to why the Survivors were kicked off the Slaters' boat or an ironic statement in reference to the Left 4 Dead 2 Survivors (who have to battle through the Hard Rain campaign simply to get hold of diesel fuel for Virgil's boat). During the comic, Francis mentions the Slaters' marriage is troubled. A telling point is that in the comic, the Survivors are presumed to be Carriers. If true, then they may have unintentionally infected John and Amanda, but whose infection resistance held out long enough to disarm the Survivors and maroon them on the shore. A final hypothesis is that the Slaters were immune/Carriers in desperate need of weapons and crafted a simple hustle to obtain them.

However, fate appears to have intervened because their boat (The Saint Lidia II) can be found partially sunk in The Sacrifice, suggesting that the Slaters did not survive upon arrival in Georgia. Nevertheless, this could be a coincidence (or simply a visual programming shortcut) since another Saint Lidia II is floating safe and sound next to its sunken sister ship.

John's voice actor is John Patrick Lowrie, who voiced the male Citizens and Resistance Rebels from Half-Life 2 and the Sniper from Team Fortress 2.

Plane Pilot
The plane pilot evacuates the Survivors out of Newburg in the Dead Air campaign. In the comic, Francis mentions the plane later crashed. It is unknown why this happened or what became of the pilot.

There is a chance that because the Survivors have been identified as Carriers they could have unintentionally infected the pilot and not have realized it.

The pilot is voiced by Gary Schwartz.

Rescue 9
Rescue 9 is not just one person, but a platoon of soldiers, who respond to the Survivors when they communicate via radio. Rescue 9 sends out an Armored Personnel Carrier to pick up the Survivors at the end of the Blood Harvest campaign. The Sacrifice comic reveals Rescue 9 brought the Survivors to Millhaven instead of the Echo Safe Zone, in order to find a cure to the Infection. In addition, the comic reveals one of the soldiers in the APC was Lt. Mora, who personally drove so he could witness the Infected for himself.

Due to some of the unused lines, one could think the farmhouse was supposed to be blown up after the truck picked up the Survivors.

Virgil
"Now this is a'far as Virgil goes, but y'all can make it to the bridge from here."

- Virgil

Virgil is a character appearing in Left 4 Dead 2. He has a Cajun accent. He pilots the escape boat in Swamp Fever, has the Survivors gather fuel on the mainland and return to the boat in Hard Rain, then drops off the Survivors at the beginning of The Parish. Virgil may be immune to the virus, or a Carrier and is saving Survivors out of good will and to use them to gather fuel.

He is now a widower after his wife was killed by an Infected bite, and will occasionally refer to himself in third-person. His boat is named the Lagniappe, a reference to the Louisiana custom of the same name, meaning a small gift given to a customer by a merchant at the time of a purchase. Out of all of the evacuation personnel in the entire Left 4 Dead series, Virgil is the only one who is known to have survived his encounter with the survivors.

There is a joke on the Steam forums that states that Virgil is a talking boat. This "theory" is substantiated by Chet Faliszek who stated that "Virgil is not a Man" when someone asked why Virgil existed during the "Last Man on Earth" Mutations.

Virgil is voiced by Randall Newsome

Papa Gator and Rescue 7
In the start of The Bridge in The Parish, two soldiers can be heard speaking over radio. They are known by their codenames "Papa Gator" and "Rescue 7". They arrange for the evacuation of the Survivors from New Orleans.

Custom Campaign Survivors
Custom created Survivors or NPCs are created by the community for their custom campaigns and not by Valve.

Crazy Ron
"Well this here is Crazy Ron riding the night train. Any Survivors still out there got your ears on, well I'm your last fucking hope..."

- Crazy Ron

Featured in both Suicide Blitz and Suicide Blitz 2, Crazy Ron is a Survivor who drives a train all around Fort Harris County searching and aiding any other Survivors within the city to get to the Fort Harris County Stadium for evacuation. He can be heard throughout both campaigns blowing the horn of the train and will contact any other Survivors by radio. However, there are some other Survivors who hate and don't trust him due to his absence when promising aid which lead to the death of their teammates while waiting for him to show up (as stated in some Graffiti).

Nondescript Survivors

 * See also: Graffiti

As well as the eight playable Survivors, there are also known to be many more uninfected humans fighting the Infected and trying to escape the area that the twelve campaigns take place in. All except the chopper pilot and Whitaker remain unseen and most are unnamed; however, they are evident by graffiti left around most of the chapters, mainly in the safe rooms. The safe rooms themselves are proof of other Survivors, as they are pre-created before the playable Survivors get to them, which implies other humans have created the safe rooms to give other Survivors a place to rest and stock up on ammo. Also, mostly in city chapters, gunfire can be heard in the background.

In some graffiti, it is also stated that there were more Survivors who were immune; whether they're immune or not, however, is not mentioned.

The Survivor's perceived relative scarcity of other nondescript human survivors is hinted at in Left 4 Dead 2's The Passing campaign, which features a sexual innuendo dialog between Nick and Rochelle wherein Nick implies that she cannot afford to be choosy as there are "only about ten men" left on Earth.

Keith
A friend of Ellis'. He is often mentioned in stories Ellis tells while in a Safe Room. If Ellis' stories are to be believed, Keith has suffered from third-degree burns over a major percentage of his body twice (95% making fireworks, 90% deep frying turkey), lost two fingers and a thumb to frostbite, broke both of his legs after driving his car off a cliff, been stabbed by "a guy dressed up like a ghost", was tear-gassed by the police (the effects of which lasted for a year), sneaked a paintball gun on a roller coaster, got attacked by an alligator, bombed by the military (among the bombs, Ellis claims, were nerve gas and cluster bombs), (nearly) drowned in the Tunnel of Love, has done time in prison, got cut up by his own "bumper-car" lawnmower leaving him with wounds over 90% of his body, got cement paved over him in a sewer after falling down an open manhole, lived in a graveyard for a year after getting kicked out of his house, invented several types of soft drink, hung spit on the overhang in the Tunnel of Love, fell off a roller coaster onto the tracks with the ride still going, got a tattoo on his forehead saying "I'm a moron" for a dare, winning $200, ate three pounds of raw chicken (the in-game subtitles say catfish), he no longer recognizes his brother Paul and lost sensation in his right foot because of the three pounds of chicken, attempted to build a house out of mud, was attacked by owls, turned a recreation of Colonial times into a raccoon fight in his backyard, pretended to be homeless, had a water balloon fight with balloons full of urine, drove across a river without using the bridge, married a couple, and would have even gotten married himself, had he not ran away from his wedding.

It is likely that Valve simply added Keith as comedic relief in the serious game. At one point during Hard Rain, Ellis even confuses the Survivors fighting their way through the burning hotel in Dead Center for something that happened to Keith. It is unknown if Keith is still alive and/or uninfected or even real. If Keith is real and is indeed alive, it is very possible that he is fighting the Horde, seeing as so many incidents failed to kill him. However, in certain cut lines, Ellis states that Keith was evacuated, claiming he was the first on a helicopter.

There are two pieces of graffiti that make mention of a "Keith", but don't specify if this is the same man that Ellis is friends with: One piece of graffiti in The Lighthouse reads, "My name is Keith Marshall (new line) And I'm going to die here", which, if this is the Keith that Ellis is friends with, could mean that Keith has made it to the lighthouse, but he has given up hope. Seeing as The Lighthouse is in Left 4 Dead,  and seeing as Left 4 Dead 2, in which Ellis talks about Keith, takes place a week after the start of Left 4 Dead, he could have already died. There is also graffiti written that reads "Keith: Waited 3 days at the meeting spot after we got separated. I can’t wait anymore. Meet me at Mercy Hospital – Krista "

After contacting Gabe Newell, asking if Keith is actually real, he answered saying, "Keith isn’t imaginary, except, well, it is a video game, so it’s all imaginary".

Ellis sometimes mistakes the Fallen Survivor for Keith, but then notices he isn't Keith.

A full listing of stories concerning Keith by Ellis can be found here.

Jacob
Rochelle mentions a man by the name of Jacob. No other information about Jacob has been said by Rochelle. Jacob might be a close friend to Rochelle, a boyfriend, a family member or an acquaintance  from her old place of work.

Distant Survivors
In the campaigns Dead Air, No Mercy, Crash Course, and sometimes at the end of The Town (as well as the main menu), occasionally, a distant gunshot, explosion, or gun burst may be heard. It can only be assumed that these are other Survivors fighting off the Infected. As they are infrequent, however, it is likely that few of them survived, or simply moved out of hearing range. Not to say that none of them do, as, from The Sewer, looking very closely at the roof of Mercy Hospital in the distance, a white helicopter (different from the red, white, and blue chopper used by the Survivors) can be seen flying in and out, hinting at more than one evacuation.

The helicopter pilot will also sometimes comment to the Survivors "Looks like you're gonna be my final run.", further indicating that he had been saving other Survivors from the rooftop. As this may be true, in Crash Course, Francis and Zoey fight constantly over the dead pilot. He can be heard saying he had an "incident", and that maybe he is trying to help you get away as far as he can before transforming into an Infected. He seems aware that he is going to die. He was going to be in the game, or at least the sound files were, but what he said during Infection left players with a bitter taste after their victory, so his audio files were never introduced into the game when it was first released. The audio clips do activate with the Crash Course DLC installed, however.

It should also be noted that the pilot's model seems to be in Left 4 Dead 2 taking the Survivors from the finale of Dark Carnival and eventually crashing, as in Crash Course.

Chicago Ted
Chicago Ted is an unseen character whom claims that "No Zombie Is Safe From Chicago Ted", the name may be a reference to Ted Phillips, the president and CEO of the Chicago Bears in 1999.

Chicago Ted has also gained a Chuck Norris-style reputation among players being featured on modded maps and in low complexity humor.

The Midnight Riders

 * See main article: Midnight Riders

The Midnight Riders are a Southern rock band who were supposed to play in Whispering Oaks Amusement park, but due to the Infection, they had to cancel, so they were picked up by a helicopter. Their status is unknown but the pilot was fine (at that time) so one can assume they were when they were dropped off. They are mentioned several times throughout Dark Carnival but never encountered, though one can occasionally see their tour bus speeding by in The Underground.

They have their own webpage which can be found here. http://www.midnight-riders.com/

Angels of Death
The Angels of Death are a group of Survivors who appear to be rather successful, and very proud of their accomplishments. They appear through graffiti twice in the Left 4 Dead series, once in Crash Course and once in The Passing, each time drawing a collection of customized skulls labeled with the members' names. Originally, there were seven members (Brenda, Jerry, Chris, Phil, Sean, Brock, and Jason), but during the course of the next week, they collected an eighth member (Jaime), making them the largest known group of Survivors.

Like the original Survivors, they probably started out in the greater Philadelphia area, as their first set of graffiti can be found in Whitney County, and over the course of the infection have traveled at least as far south as Rayford, Georgia. In Whitney County, they marked 600 tally marks, presumably representing the Infected they killed while held up at that point. In Rayford, they make the claim that they are "clearing the way" for other survivors, killing every infected they come across - though this does not explain why there are still numerous infected in both campaigns other Survivors cross.

Their cockiness does not seem to be taken well by other Survivors. In Whitney County, their graffiti is commented on by others writing "Sick Bastards" and "World coming to an end and they are drawing pictures".

Characters from The Sacrifice comic
The following characters are only encountered within the Left 4 Dead comic released with The Sacrifice

Ray
Ray was a fellow co-worker and friend of Louis at a business called "Franklin Brothers" in Philadelphia PA, until two days after the first Infection. Ray decides to call in sick to work much to Louis' dismay, claiming he does not want to go to work because of the rapidly spreading infection and would rather stay home than risk getting exposed to the Green Flu. His fate is unknown.

Wade and Carolyn
Wade and Carolyn are Zoey's parents, who are either divorced or separated. Zoey was living with her father at an apartment near her college for one semester, while Carolyn lives at their family home with a man named Kevin. Her mother is upset that she wants to quit college after just one semester, while her father is more easygoing and thinks she would do well in the family business in the police force.

Unfortunately, Carolyn is bitten by an intruder, turns into an Infected and ends up attacking Wade, who shoots Carolyn. Wade reminds Zoey of all the zombie films they watched when she was younger where the protagonists have to shoot someone before they turned, which she does after their final words of love with each other. Zoey is horrified to learn later on from the Doctor that the Carrier gene runs on the father's side, meaning that her father may have been immune to the Infection.

Sandra
Sandra was Francis' girlfriend, seen at a bar with him and his friends. Francis doesn't seem to know her that well, as he keeps calling her "Becky". She ends up turning into an Infected while she and Francis are kissing in a back room at the bar, vomiting on his vest and biting his neck. She goes to finish him off but is shot by Francis' friend Duke. It should be noted that her figure after becoming Infected bears resemblance to a Witch (though she also appears to pounce at Francis like a Hunter, and she vomits on him like a Common Infected or Boomer ).



Duke and Danny
Duke and Danny are friends of Francis. When Francis' lover Sandra turned into an Infected and he didn't realize that she was about to kill him, Duke shot and killed her with a shotgun. Duke may be considered one of the more conscious-minded characters, albeit extremely paranoid. He wears a Midnight Riders T-shirt and appears to believe in government conspiracies, stating that heroin, satellites and cell phones were somehow always meant to lead up to the zombie apocalypse. Danny was the only other one to aid Duke in carrying the Jukebox to the rooftop of the bar and join in with their gang in the shooting spree. Their fate or how they got separated from Francis is unknown.

Major Everly
The man in charge of Millhaven, Major Everly does not believe in the Special Infected's various abilities, nor in their existence, and refuses to believe the Infected are capable of climbing the twenty foot walls surrounding Millhaven, and the existence of Smokers and Hunters that can easily destroy the formation of the guards. Major Everly is eventually overthrown by Lt. Mora after the Lieutenant sounds the alarm and storms into the Major's office with two other soldiers from his platoon. While Mora and his soldiers attempted to make their way out of the facility, Everly rallied those soldiers still loyal to him to attempt an evacuation via helicopters. Unfortunately, the rampaging Tank that killed Mora attacked Everly's helicopter as it was departing from the base and threw it at the Survivors, causing it to explode and kill all of its passengers.

It is interesting to note that during Mora's mutiny by sounding the siren, Everly asked if Mora knew what he was doing. Just before this, Zoey and Bill were informing the Doctor that infected were in fact drawn to sound. A tad more than speculation concludes that it is possible Everly knew more of the predicament than he was letting on. This is supported by his ignorance pertaining to the fact that HQ had been compromised for the last six days and never disclosing to his men, choosing to simply dismiss Mora's initial concerns.



Lt. Mora
A paranoid soldier of low rank who is concerned about the safety of Millhaven under the leadership of Major Everly, as well as believing that Carriers and Infected are as risky as each other. Lt. Mora personally took part in the rescue mission of Bill, Francis, Louis, and Zoey in order to witness the Infected for himself, especially the Special Infected. Lt. Mora believes so many Carriers in Millhaven is a bad thing, and overthrows Major Everly due to disagreements on the safety of the military outpost as well as refusing to risk his platoon in a supposedly "unsafe" outpost, or for Carriers who might as well be on the Infected's side.

During the events of Part 3, Lt. Mora fought alongside his soldiers, ensuring all of them gets to safety before he does so; however, an Infected manages to tear off his gas mask before he could get himself to safety. His soldiers refuse to help him, as he is now compromised, and decide to leave him for dead, much to his anger. After barely surviving a horde of Infected, he confronts the Survivors, who appear like monsters to his eyes; it is unknown if this is due to the Infection or just as a result of his dazed state. Francis comically convinces him that everything is Louis' fault, but before he can attack, he is punched by Bill and decapitated by a rampaging Tank.

Jeff and Annie
Soldiers who guard Louis and Francis' cell at Millhaven. Louis explains to them the various Special Infected, which they know nothing of (the only exception being Lt. Mora giving them the name of the Smoker). When the compound is attacked by Infected, Jeff and Annie follow Louis' instructions in avoiding a Witch, which they repay by freeing the two Survivors from the cell and taking them to the armory to get firearms. They encounter a soldier-turned-Boomer, which Jeff shoots at initially, but is thrown off-balance by Louis while Francis dispatches it. Jeff then arms Louis with a pistol, while Francis takes one off the now-dead Boomer.

Jeff and Annie allows Louis to take point due to his superior knowledge of the Infected. During Part 3, both of them along with the doctor follow the Survivors, thus making them the only few Survivors making it out of Millhaven alive. Nearing to an end, Jeff and Annie decide to leave for another choke point, stating that their gas masks might eventually fail. However, when they reach a point, they realize that there are no other soldiers and make a dash to the train, hoping to catch up with the four. Annie was last seen being attacked by the Infected at the end of Part 3. Jeff is not seen in detail at any point after the scene of them holding out against a large horde, but is presumed dead. However, there is a little chance that Jeff survived.



The Doctor
A doctor at Millhaven, who collects saliva from Zoey in an attempt to find a cure. He is pessimistic about his chances, and states that the Army will kill him when they realize he can't stop the Infection, as he is a carrier. He offers to help Bill and Zoey escape from Millhaven, providing they can get him out as well. He accompanied the Survivors from Part 2 to Part 3, and attempted to tag along with the Survivors to head down to the south. However, he failed to get on the train before Bill started it up. His final moments show him being pounced by a Hunter while reaching out just inches from the train's door until the Infected swarm him. Zoey, wanting to help him, tells Bill to stop the train. Bill, however, ignores her, and the Doctor is believed to have been killed. As a consequence, Zoey detests Bill for this action (as seen in the beginning of The Sacrifice)

Rivera
A soldier guarding Zoey and Bill while they are tested at Millhaven. He outraged Bill and Zoey when he threatened her at gunpoint, so Bill distracted him while Zoey hits him with it. His gas mask being dislodged in the struggle, Rivera entered a state of panic, fearing infection from Zoey and begging her not to approach him. His fate is unknown as he is carried off by another soldier who arrives on the scene when the Doctor shouts out "Rivera's down!". His ultimate fate is unknown, presumed to be dead as the military was known for taking no chances with those possibly infected.