Highly trained military veteran Markus returns home to care for his daughter after his wife dies in a tragic train accident. Meanwhile a survivor of the explosion, mathematics geek Otto, becomes convinced that the incident was part of an assassination plot involving dangerous crime gangs. When Otto and his hacker friends, Lennart and Emmenthaler, decide to confront the short-fused Markus with their suspicions, a chain of events begins which leads the mismatched group into a violent and ill-conceived revenge mission.
