When the prestigious Dr. Arne Lundell completes the most important work of his life, a colleague from the University of Stockholm, Dr. Sander, complains against him for plagiarism. Marianne, wife of Arne, does everything possible to encourage her anxious husband for not understanding the reasons for this unjust accusation. In these circumstances, Sander is found dead. It seems that it is a suicide, but his soon finds that he has been murdered. Suspicions fall on Dr. Arne. The dramatic situation begins to unravel when Arne discovers, by chance, a letter by which he discovers that his wife was the secret lover of the missing professor.