Nuclear security expert Katja Wernecke (Ulrike Folkerts) helps cover up a fire in the German nuclear reactor she works in, before the government takes a decision on extending the usage license for it. But the press uncovers it. PR man Steffen Stratmann (Matthias Koerbelin) is brought in to improve the companies image - but before he can implement his plan a nuclear meltdown occurs. 2m people have to be evacuated. Wernecke re-enters the hot zone to investigate the cause...