In England, a famous jewel collection is stolen. The police suspect that the jewels have been smuggled to Sweden, and in Stockholm, the young insurance detective Peter Holmer is commissioned to trace the stolen jewels. The tracks first lead Peter to a certain ballet master Lando, but when he comes to Lando's flat, he finds him murdered. Before the police were summoned, Peter saw a young lady smearing from the floor. He tries to catch her, but when he gets down the street she disappears in a taxi..