Army surgeon Johan Gustav Daadh gets offered the job of district police commissioner as he's seeing a patient home in Stockholm. He's also fallen in love with the chief constable's wife, Magdalena. When he realizes that Magdalena believes in him, he accepts the position and takes on his former patient, Simon Freund as his assistant.

A shop owner is found dead with a knife in his chest. A man has been caught red-handed, but Daadh isn't satisfied with what seems to be the obvious. He takes a different approach and reaches a surprising conclusion. One of his friends from the old days needs protection, but their meeting suddenly makes Daadh the focus of a vengeful woman's rage.

When Daadh goes to interrogate the person who printed pamphlets libeling the King, he finds the man murdered, his skull crushed in his own printing press. Daadh's investigation brings him in contact with a radical young French woman and with Marta Raxelius, who's convinced that Daadh killed her brother and will stop at nothing to get her revenge.

A cunning burglar is wreaking havoc in Stockholm. As the panic spreads, Daadh is under pressure to apprehend the masked thief, who's known to be dangerous and violent. He's offered help by the renowned hypnotist Cagliostori, who happens to be performing in the city. Daadh allows himself to be hynotized, unwittingly putting his own life in danger.

A bomb explodes in a packed coffee house. Daadh's investigation is interrupted by an order to stop the illegal church services held by a pietistic congregation, of which Simon Freund is secretly a member. When a priest from the state church is found burned to death, Daadh suspects a link between the two murders and that the perpetrator is in close proximity.

One of Daadh's old radical comrades is accused of treason and hung on the square. His body is supposed to go to Uppsala University for dissection by medical students. When the body disappears and two more murders take place, Daadh realizes that someone will kill indiscriminately to prevent him from uncovering a dangerous truth.

A number of children are found dead in the great piles of excrement and trash that line Stockholm's shoreline. Daadh's investigation leads him to the Great Orphanage, where they claim to know nothing about the bodies. Each year, one of the orphans is chosen to carry out the drawing in the Number Lottery, a popular event where large amounts of money are in play.

A landowner is found dead in his stables, kicked to death by his horse. After Daadh determines that the accident was a murder, he has no difficulty finding people who bore grudges against the victim. Any member of the victim's family could have done it, but the evidence is scanty and the Police Chief is demanding that someone be found guilty.

Daadh is invited up to Uppsala by his own professor, who needs his help finding out who poisoned one of his students. Daadh involves himself in the case and quickly realizes his own life is in danger. Meanwhile, back at the Wahlstedt home in Stockholm, subversive events take place that will affect his future.

With friends gone and his worst enemy closing in, Daadh's world has been shaken to its foundations. Because of his courage and his ability to see patterns in seemingly unrelated events, Daadh succeeds in using the challenging circumstances to his benefit. But he's also harshly confronted by his own past and forced to bargain with those in power.