Reactor is a map used for the missionsDay 8: Fallout (Security) and What-If: Critical Reaction (Resistance).
Reactor is a two-part map.
The Resistance must hack a fan access panel to reach the main reactor controls, then plant a bomb on the controls so that the reactor melts down. It's deemed a "What-if" in respect to the Resistance campaign because the sequence of events leading up to it require Security to prevent the Resistance from freeing their pilot.
Starting Time: 10 minutes
Time added for Hacking: 10 minutes
Repairing the Bridge Access Panel raises a bridge to let Resistance players to drop down over Security and giving the tactical advantage of High Ground.
The reactor, originally not on the Ark, was built after refugees started pouring in. Originally, the Ark was meant to be the epitome of "green energy", perfectly environmentally friendly, clean, and efficient. When the refugees started arriving, however, the clean energy wasn't enough to sustain the suddenly grossly overpopulated city. In desperation, the Ark's owners ordered the construction of a massive nuclear reactor to power all of the new inhabitants.
The Resistance, now in the city (through unknown means as of now), targets the reactor, not to spite everyone, but to stop the Security's 'war machine', so that they can overwhelm them and become citizens of the city.
Critical Reaction, the mission available to the Resistance, opens with the voiceover of an unidentified Resistance member who has taken Chen's words literally and is willing to risk a nuclear disaster to equal out the living conditions of the Guests and those who live on the Security side of the Ark. He states that it is only just for the Resistance to do so, as those on the Security side will never understand the true difficulty and unfairness of the Guests' lives until they have actually experienced it.
When the Resistance have succeeded in detonating the reactor controls, the player watches as the reactor explodes, venting nuclear radiation into the sky until the Ark is surrounded by dark radioactive smoke. Meanwhile, Chen has discovered the plan and its success and cries out in anguish as he realizes his threats were taken literally and that he was too late to call the mission off.
In the Security's mission, Fallout, Mokoena reveals to the player that a message had been intercepted by the Founders, the same one that is given to the player if they play as Resistance. The Founders perceive this as a grave threat and Mokoena sends the player to defend the zone to prevent such a disastrous event from occurring.
If the player succeeds, Mokoena breathes a sigh of relief and informs the player that he has successfully saved the Ark from the Resistance as the Resistance members are seen retreating out of the facility. While the ending cutscene begins playing, the player will receive a trophy/achievement for successfully completing the canon part of the Security campaign.