Gereon Rath uncovers a dangerous web of shadows in a criminal case involving the Berlin mafia.

Rath investigates the missing film reel; an informant helps with the Russian revolutionaries.

Rath receives an uninvited guest in his apartment.

Communist protesters and police engage in a May Day stand-off.

Berlin becomes increasingly politically charged.

Rath faces a moral dilemma as Bruno makes a power play.

Rath relives painful memories of the front.

Rath and Bruno finally get a lead in the case, but there are consequences.