The Tunnel

The Tunnel is the second chapter of the fourth campaign, Blood Harvest. The Survivors must fight their way down through a repair warehouse for for train cars. Once they've made it to the ground floor, they're forced to open an emergency door which will activate an alarm and trigger a crescendo event. Once the Survivors have fought through the horde, they must move onto the train tracks following them north. When they reach an obstruction far down the tracks, they take a left and head into a safe room.

Campaign
When starting from this chapter, the AI Survivors will grab:
 * Bill will grab a submachine gun.
 * Francis will grab a pump shotgun.
 * Louis will grab a pump shotgun.
 * Zoey will grab a submachine gun.

When the Tier 2 weapons are found, they will grab:
 * Bill will grab an assault rifle
 * Francis will grab an auto shotgun
 * Louis will grab an assault rifle
 * Zoey will grab a hunting rifle

Otherwise, they will keep the weapons they had in the last chapter. (See The Woods for a list of weapons they will grab there.)

You start in the freight house on the third floor of a repair building for train cars. Similar to the early levels of other campaigns, there are only Tier 1 weapons in the Safe room. Heal up, gear up, and head out.

You will exit out into a hallway with two rooms on your left and a room with a descending staircase to your right. The two rooms to your left often contain pills, molotovs, pipe bombs, or an extra pistol. If you feel up to it, search these two rooms for items. Once you're ready, travel down the stairs to the offices. Once you're in the offices, there is a possible spawn point for Tier 2 weapons on a table. This table is next to the window that you must exit through and out onto the warehouse catwalk. Note that the offices are often home to pills, grenades, and an extra pistol.

Once you are on the catwalk, proceed along it and descend a yellow beam to ground level. Remain vigilant and ready, however, as this is a possible Tank spawning location. If he does spawn here, it is a fairly good place to fight him because you have a lot of space to move around.

In the room ahead of you, there is a door. Outside, there is a table with either ammo and pills, or Tier 2 weapons. In the room behind the door, there is an emergency exit with the words "Emergency Exit Only, Alarm will Sound" written on it. Also in this room is a medical cabinet with pills and rarely, a first aid kit. Make sure everyone is in the room and then close the door before opening the alarm door.

The emergency exit triggers a crescendo event, so be prepared. There are a few ways you can approach this:


 * 1) The first, most common, and generally easiest method, is to fight from the room where you activate the door. If you break the crates at the back of the room, all four Survivors can put their backs to the wall and fight from there. When simply fighting from the centre of the room, Infected can attack you from three different directions - the two opposite doors and from the vent above. However, if you do fight with your backs to the wall, you can group all three entrances in front of you. This effectively means that they only attack you from one direction.
 * 2) The second method is to fight from the corner beside the table with ammunition or tier 2 weapons. The advantage to this is that your team cannot be attacked from behind and they effectively have infinite ammunition.
 * 3) The third method is to open the door, close the door, and backtrack to the large train shed for combat on open space. Whilst effective, this method is also dangerous and is therefore not recommended on higher difficulties.
 * 4) The final, and least recommended method is to "out-run" the Infected. Prepare your team, and charge out once the door is open. By moving far enough down the level, the crescendo event's Infected will stop spawning. This method can lead to horrible situations where the Survivors encounter a Tank in front of them, and turn to leave, only to find the horde behind them. Due to the extremely high risk, this method is only recommended if you are not playing to win and you're playing on an easier difficulty.

The emergency exit door leads to a big room containing large cisterns. There's a staircase ahead of you. You can either head up there and follow along the catwalk, or simply head to your left. If you choose the catwalk, you can exit out onto an overhanging roof and drop down to the tracks. Otherwise, heading to the left will lead to a door which also leads out onto the tracks. Either way, you'll have reached the train tracks, and you need to follow them north. This means into the tunnel. The table just outside of the tunnel can hold either pills, molotovs and pipe bombs, or Tier 2 weapons.

There are multiple ways through this tunnel. They do, however, each lead to the same destination. Eventually, you'll reach an obstacle that you cannot pass. Here, you will need to take a left in to a service passage, and follow it into the safe room. Be careful, this is where the Director's nasty sense of humour shines. A possible spawn point for the Tank is in fact, directly in front of the safe room. Many teams have limped their way into that passage, only to have an angry Tank storm around the corner and incapacitate them all. Listen out for his angry grunts, and don't rush over there by yourself!

Whether he shows up or not, get into that safe room and close the door. Phew, safe at last! Take a break, and then prepare. You've got The Bridge to cross!

The Survivors
Now that humans are controlling the Special Infected, things can only get harder. However, they can't spawn until you leave the safe room. That doesn't mean that you should let them have a good chance to find just the right spot, though! Hurry up and get your supplies, and get running!

Throughout the level, keep in mind that you are playing against human players. They will not wait for you to come to them, and if they do, it's because they have an ambush location that could be deadly to you and your team. With this in mind, you need to keep moving. However, moving blindly could be your downfall - move quickly, but with caution.

This level is not too bad for the Survivors. There have certainly been worse levels, but overall, you have a fighting chance against the Infected. Remember that your enemies will try to anticipate your moves and will attack when you are vulnerable or alone. Keep in mind the locations that you'd hate to be attacked in and exploit your knowledge as an Infected.

The crescendo event will be problematic for an inexperienced team of Survivors. If you utilise the methods for campaign mode, you should be alright. However, remember that your enemies will most likely be aware of these tactics and will exploit their weaknesses. Stick together and cover each other's backs. Make sure that everyone is still standing and not being attacked by Special Infected.

This level is a Tank nightmare, it is nearly entirely indoors or in close quarters. The Tank can rip apart any Survivor team, especially a human-controlled Tank. Bear in mind the locations he will spawn and how best to deal with him. Also remember that he can spawn right in front of the safe room. This is one of the worst places for him to spawn as not only is it in close quarters, but it normally takes a tired team of Survivors by surprise.

Also concerning the safe room, when you know you're near the safe room, make sure you are with your teammates before you make a dash for it. If you make a break for it alone, it is not unlikely that a Hunter will be waiting for your arrival and possibly kill you before the others can reach you. Or worse, the aforementioned Tank will spawn. No one can survive the infection alone. Teamwork is essential.

The Infected
Boomers: This level was made for you. You are the sneaky one, hiding around corners and in dark rooms. You stalk your victims, wait for them to be distracted, then - attack! Vomit spews in their direction, they scream rants of anger as they back into defensive positions; waiting to embrace the force of your approaching horde. The interiors of this level are perfect for Boomer ambushes. There are many corners that the Survivors must pass on their journey. If a Tank shows up, do your best to cover as many Survivors as you can. A horde and a Tank at one time is often enough to overwhelm the Survivors. Although rooftops aren't your forte, go for it! You can wait on the rooftop for the Survivors to emerge through the windows below you. Then, you can rain down your putrid bile! If you can cover the Survivors while other Infected are in position, Smokers and Hunters can use the opportunity you created to put the hurt on the Survivors. There's a Witch? Conceal her! Odds are that one genius Survivor is going to shoot you and the Witch in one go.

Hunters: Certainly, you are a deadly foe worth marvelling, though it's a general rule of thumb to see your prey before they see you and revel in your excellence. Hunters work best in ambush situations. Another rule is to not attack a group unless you're trying to distract them, or simply scare them. Try to hide in small spaces, though. Pounce people who wander off. Always remember that you have a strong melee attack, so if you can't quite pounce, feel entirely free to melee. Hiding around Witches and cars with active alarms is also quite devilish, and effective. Remember all of those times you were pounced by a Hunter and it couldn't have happened at a worse time? Well, exploit that knowledge. Think like a Survivor, and attack when they're vulnerable.

Smokers: Indoors. This is not so great for you. However, the interiors are generally wide open. Open spaces are generally good because you can drag them far away from their friends. Closed spaces are not so good. Experienced Survivor teams will often adopt a "squad formation". This usually consists of three facing the front and one covering the back every so often. Let this be their downfall and snag that rearguard. With no-one else watching the back, it may take the Survivors a few vital seconds to realise what has happened. As with the Hunter and the Boomer, don't underestimate your secondary melee attack.

Tanks: Here the Tank is strong. Where is he not? He can strike with swift precision and force, breaking through walls of Survivors and charging through seas of lead and fire. Perfect. As with most interiors you are a force to be reckoned with. You can be the very difference between victory and defeat. However, these interiors are fairly open. Because of this, your rock-throw attack can be a life saver. Or a killer, which ever way you want to put it. As long as your enemies are not a team of perfect players, you should be able to do a large amount of damage to those immune annoyances.

Survival
Crates Method


 * This method involves fighting from the room where you activate the door. If you break the crates at the back of the room, all four Survivors can put their backs to the wall and fight from there. When simply fighting from the centre of the room, Infected can attack you from three different directions - the two opposite doors and from the vent above. However, if you do fight with your backs to the wall, you can group all three entrances in front of you. This effectively means that they only attack you from one direction. When the Tank arrives, the team can exit through the door to the right and fight him out on open ground. Once he's been dealt with, repeat the method until you get yourselves killed.

Boxes Method


 * This method's strategy is to find two of the tall shelves holding crates and boxes and sandwich your team in between them. If you find a decent one, you can have the Infected only attack you from the front, however, the Tank cannot be dealt in this way. As with the previous method, it is best to head out on to open ground and fight him from there. Once he's dead, return to your position and continue the fight.

Hidden Cargo Method


 * Do not alert the horde just yet. There will be a lot of crates on one of those big shelves. If you climb up there you will notice a little gap in the boxes. You and your teammates will be able to drop down there. Once in there, immediately crouch. You will be unnoticed by every type of Infected. This method is very tedious but you can stay there as long as you want and not get caught.

Rooftop Glitch Method


 * This glitch allows up to two players to be standing on the roof of the warehouse, where none of the Infected can reach you. First, incapacitate all non-human Survivors. Keep in mind you will need at least three human players to perform this glitch. At the start of the round you will see a fallen yellow beam that acts as a ramp to a platform. Go up the beam and look to your left. There will be partially destroyed railing. Jump on top of this railing and then jump forward and move backwards to be incapacitated and holding onto the rail. Now, have two human players help you up. The primary rescuer will help you until the "revival bar" is at 90 percent full. When it is at 90 percent, the primary rescuer will let go. The secondary rescuer's job is to hold the help button the whole time, until the primary releases. When the primary releases, the secondary will continue to help the Survivor up. Continue that cycle for about 2-3 times and the hanging Survivor will be on the roof of the warehouse, safe from all danger. The other players will then alert the horde. They will most likely die, but that does not matter as long as the player on the roof remains alive, the timer will continue for as long as they wish to stay.

Trivia

 * The alarm that activates when the door opens will eventually turn off. It is unknown how or why it turned itself off.
 * Although it is marked as an "Emergency Exit", there is no other way for the Survivors to progress.