Rath awakes after a long night to be face a new case - the massacre of the Red Fortress.

Gereon Rath is reunited with Helga, but his joy is short-lived.

Rath and Graf undertake a dangerous mission to recover evidence of the secret German airfield based in Russia

Rath and Graf undertake a dangerous mission to recover evidence of the secret German airfield based in Russia

Lotte is kidnapped and held in an ominously familiar location, while Rath and Benda's case against the Black Reichswehr stalls.

Crucial evidence falls into Rath's hands, while Lotte unearths a conspiracy to murder an international envoy.

Rath and Lotte race to stop the train robbery in time, while Greta's conscience is torn when she falls into an assassination plot.

Rath faces a stand-off for train carriage TY 23-05, and the truth behind the Sorokins' gold is revealed.