Jaz's game developer colleagues celebrate the completed reboot of their horror-survival adventure Pulse, but disturbed security officer Eddie wants everyone to play the game for real.

As the building's inhabitants begin to suffer the fatal effects of the EMP bomb, Errol, Caspar and mysterious newcomer Dom realize Jaz has a survival advantage that could save them all.

Caspar battles invasive flashbacks, Errol slips further into his game persona, Eddie finds a useful ally in an embittered audio expert, and Jaz risks their safety to rescue another survivor.