In the morning twilight of Prague, the dead body of the safe-breaker Toufar is found floating on the river Vltava with a knife in his back. Police inspectors visit Toufar's lover, the prostitute Anna Kulatá (Jirina Bohdalová), nicknamed Umbrella, and it is apparent that the moment before she opened the door of her flat, someone fled through the window. Umbrella is summoned for examination to the head of the criminal police - Police Councilman Vacátko Jaroslav Marvan, but although shocked by the ...