A respected engineer named Josh is asked by his company to inspect a Nuclear Power plant in Russia. He's reluctant to go, but when he discovers there has just been a minor earthquake in the region he changes his mind. His ex-wife, Rachel, works at the plant, and his children live there with her. When he arrives in Russia, he's taken on a tour of the power plant by the manager. Rachael is checking the nuclear core after the tremor, concerned that there might be a leak in the coolant system that's causing it to overheat. Later that night Josh studies the readouts from the plant and discovers an anomaly. The core is seem to be overheating. Rachael and Josh must find a solution to stop the core from overheating.