On a summer night, the eve of Ivan Day, a group of young people gathers in the Hagestadt National Park. Two girls and a boy, dressed in eighteenth-century costumes, drink wine and sing old dining songs. During the height of the fun, someone cold-bloodedly shoots all three from behind the bushes. The bodies of the young people disappear without a trace—yet two months later they are suddenly found at the place of the murders. Is this the prank of a madman, or a challenge thrown at the police, which is unable to solve the crime?