Tom Blixen worked in Russia for a long time, but was forced to return to Sweden. He begins to work in the energy company "Beekraft." Unexpectedly, after a meeting with a high-ranking Russian official, the general director of Suekraft falls ill and dies. As a result of the investigation, it turns out that he was poisoned with polonium. Suspicions immediately fall on Russia. Crime reaches a new level when the safety of one of Sweden's largest nuclear power plants is at risk. Tom Blixen and former police officer Sonny Helqvist begin a hunt for a criminal to prevent an international conflict between Sweden and Russia and a potential nuclear disaster. "Sleeping Agent" was published in connection with the 30th anniversary of the Chernobyl disaster.