A cunning burglar is wreaking havoc in Stockholm. As the panic spreads, Daadh is under great pressure to apprehend this masked thief, who is known to be both dangerous and violent. He is close to getting caught, but escapes, whereupon Daadh is offered help from the renowned hypnotist Cagliostori, who happens to be performing in the city. Daadh allows himself to be hypnotised, falls asleep and wakes up in a most unpleasant situation where his very life is in danger.

One of Daadh's old radical comrades is accused of treason and hung on the square. His body is going to be donated to Uppsala University to undergo dissection for the advancement of medical science. But the body instantly disappears, and the two students who were sent to take possession of it are found murdered. Daadh soon realises that his enemy Marta Raxelius must be involved in the theft of the body. But two more murders take place, and it becomes clear to Daadh that someone is ready to kill indiscriminately in order to prevent him from uncovering the dangerous truth he has got wind of. And before he realises it, his own life is also in danger.