Power Out

Power Out is the 6th mission in. Compared to other maps, it can be considered either one of the easiest missions after Zombie Pods at later levels or one of the more difficult maps due to the diversity of zombies and the unique boss(es). Due to how the map works, either playing slowly or rushing through will work, though playing slowly is recommended if you want to have a higher chance of survival.

Plot
A hospital in an infested city has lost power. There is no worry about being infected due to its strong defenses, but the only way to restore power is via four switches through the underground tunnels. The player(s) must repair all four switches.

Layout
Power Out's map has many corridors. It has a large room in the middle, with three dead SAS soldiers and other bodies scattered throughout. There are five passages from the central area, four of them leading to a switch and the other one leading to the starting point.

Players spawn at the middle-left room on the map to the right, though there are Pods in the Start in Nightmare Mode. Zombies will emerge from the walls east of the starting point, which the player must kill to proceed to the center room. More zombies will spawn from the walls of the central room, and after they are killed, exactly one corridor will open up, leading to a switch. Every corridor, when opened, will spawn zombies from the walls.

At the end of each of these opened corridors is a "switch", indicated by a large area dashed with yellow diagonal lines and the four red palm print sensors. Stepping into the designated area will automatically "repair" the switch, and more zombies will spawn within the corridor's walls. When players have killed all those zombies and have moved into the center area, more zombies emerge from the walls, which all must be killed to open up another corridor. The process repeats for the rest of the switches.

Varying zombies spawn from each subsequent corridor. After Switch Bravo, the second switch, is repaired, Zombie Turrets will activate in the center room instead of zombies spawning. When Switch Charlie, the third switch, is repaired, Zombdroid Servants and Zombdroid Soldiers spawn from the corridor in the place of regular zombies. Lastly, after repairing Switch Delta, the fourth and final switch, Loaderbots will activate in the central room in the middle when players move into the area.

The Loaderbot(s) counts as the boss(es) of the mission. Runners and Spitters will spawn within the walls of the middle room endlessly until all Loaderbots and zombies spawned from the corridor (except for Runners and Spitters spawned from the corridor during the boss battle) are killed. Afterwards, a twenty-second countdown is initiated before the mission ends in a victory.

Loots

 * At the middle-right corridor, at the fourth turn from the beginning, there's a wall that can be shot at, revealing a group of weaker zombies and two loot drops.
 * At the bottom corridor, if the player(s) follow the path to the right, at the end are three zombie pods, which contain either zombies or loot.
 * At the southern corridor, there's a secret room at the turn before the switch. When shot at, it reveals a group of zombies and two loots.
 * Each switch has a medkit next to it. In Nightmare Mode, there is no medkit.
 * In the fourth or Final Switch, there will be a loot drop and a medkit. Unlike Nightmare Mode, there is no medkit.

Tactics
Regardless if the mission is rushed or not, all zombies spawned must be killed to proceed. This means that as players rush into the center room after repairing a switch, they will still have to kill all the zombies from the corridor to move forward. As zombies pile up at the later levels, using a gun with good crowd control is advised. Multiple Bloaters, Shielders and Zombdroids spawn on one occasion, so bringing a high-damage gun is also recommended.

As player(s) enter the central room and zombies spawn, they can either stay in the middle and constantly move around to shoot the incoming zombies, or he/she can back into a corridor and have to shoot in only a single direction. Additionally, try to keep as many barricades (boxes) in good condition, especially at earlier levels. This is due to the Loaderbots that activate. At lower levels, they can outrun the player, so stalling them with boxes can be done to safely defeat them.

Loaderbots are very resistant to physical weapons, but they have only a small amount of resistance to heat and energy, and they have no defense from chemicals. Use mostly Chemical, Energy/Shock or Thermal weapons. However, with certain weapons you can safely backpedal and damage the Loaderbots without them hitting you due to their attack time

Trivia

 * If the player stays in the central area without going into the corridors when the doors open, the zombies will still spawn in the corridor
 * Unlike the infinite zombie spawns that occur during the boss fight in Zombie Pods not rewarding any exp to character levelling or masteries, the infinite Runner and Spitter spawns on Power Out do.
 * As long as one Loaderbot remains alive, the Runners and Spitters will keep spawning infinitely.
 * It is possible to trap a Loaderbot in a spawn hole in any of the walls by either pushing them in when they attack you or pushing them in using other loaderbots (including when they push themselves around to get to you). Normally the Loaderbots will walk out of the holes, but sometimes you might get one stuck inside. If and when this happens, you can't release it and it must be killed to continue - however only wall piercing weapons can do this, or allowing it to hit you, eventually killing its self on your CQC if you don't have any other way to kill it.

Map Specific Achievements

 * Zero Casualties
 * Map Master - Power Out