Hermann Lenschau

Scotland Yard is after a homicidal maniac called The Blue Hand, which is what he uses to kill his victims.

When the Paris airport management is informed by telephone that there is a time bomb on board a Canadian Atlantic Airways plane to Montréal, they initially believe it is a bad joke. But the caller answers again. Inspector Bignon gets involved...

The sister of a famous, but as yet uncaught, criminal named The Hexer is murdered. Inspector Higgins of Scotland Yard believes that The Hexer will surface to take his revenge on his sister's killers, and plans to set a trap to finally capture him. However, soon bodies start piling up, and it looks as if The Hexer may get away yet again.

Berlin in 1878: Corinna Schmidt, who was brought up in a petit-bourgeois, academic family, is romantically interested in Leopold Treibel, the son of the lordly councillor of commerce Jenny Treibel – although Corinna is also deeply in love with her cousin Marcel. Leopold is also falling for cute Corinna, and Jenny Treibel tries to prevent their friendship by all means, but changes her opinion when their secret engagement becomes public. To avoid a scandal, she urges them to marry quickly. But Corinna soon withdraws from this complicated situation and again turns to her cousin, who is banished from the country for his social democratic beliefs.