Rammbock: Berlin Undead

Michael, a lovelorn man, arrives in Berlin with the intention of returning a set of keys to his ex-girlfriend, Gabi, as an excuse to see her again. Upon reaching her apartment, he finds it empty except for two plumbers working on the central heating. Michael learns from the plumber's apprentice, Harper, that Gabi has stepped out but will return shortly. Suddenly, the apprentice is attacked by his boss, who has inexplicably transformed into a violent maniac. Michael and Harper manage to subdue the crazed plumber and barricade themselves inside the apartment. Soon after, they discover they are trapped in the apartment block, which is under siege by a growing number of similarly deranged individuals, seemingly driven by a hunger for human flesh.