
Sickan, the leader of the criminal Jönsson gang is incarcerated in a mental institution, attended by Dr M.A. Busé, who admire a handbook in crime that Sickan has been writing. Blackmailed by the nefarious banker Wall-Enberg, Dr Busé and Sickan's partners Vanheden and Dynamite-Harry execute Sickan's plan of stealing the valuable Black Diamond of the Romanovs from the National Museum.
Ragnar Vanheden

Dynamit-Harry

Dr. Max Adrian Busé

Doris

Lillis
Lohman

Andersson

The Chief of Police

Wall-Enberg

Biffen Johansson

Busé's secretary

Count Romanoff

Guard
Guard

Jailer
Patient
Patient
Keeper

Unknown Role
Unknown Role

Unknown Role

Unknown Role