The Ghost Sonata relates the adventures of a young student, who idealizes the lives of the inhabitants of a stylish apartment building in Stockholm. He makes the acquaintance of the mysterious Jacob Hummel, who helps him to find his way into the apartment, only to find that it is a nest of betrayal and sickness. The world, the student learns, is hell and human beings must suffer to achieve salvation.
Four stories, all related to fatherhood, are presented: A father tries to stimulate his son by bringing him to his workplace with disastrous consequences. Richard Brunn and his wife, who run a design hotel, suffer a strained relationship as his parents visit. An extended family is gathered to find out who will inherit the wealth of a famous jockey. A cooking class develops into a therapy session.
The kidnapping of a DA's wife, the murder of several minor criminals and the police finding a large stash of weapons is all in a day's work for criminal detective Roland Hassel.