Moris Renar was one of the leading science fiction writers of the first decades of the 20th century. In addition, along with science fiction plots, Renard widely used mystical-religious, pseudo-gothic, detective and adventure themes in his works. This volume contains three works by Renard related to the detective genre. The novel "Mysterious Transformations" is an example of a real psychological detective story, reminiscent of traditional Sherlock Holmes investigations - with a mysterious murder and the use of the deductive method to solve it. The story "The Secret of His Eyes" tells the story of a young Frenchman who lost his sight in the war. The mysterious doctor Prosop replaces his eyes with electroscopes - devices that detect electricity. Here the detective-fantasy plot also has a symbolic meaning: the blindness of the mind leads to the emergence of wars, cruelty, the destruction of civilization... The story "Rendezvous" is, rather, a mystical thriller with a detective plot, written in the best traditions of Edgar Poe.