Fashion photographer Roman Belov has been sentenced to life in prison for the murder of four people. Roman is absolutely sure of his innocence, but he cannot remember what really happened on that fateful night. In prison, a mysterious man calling himself a Teacher appears to him in his dreams and offers to help him find the real killer. But how do you investigate if you're trapped in a stone bag? And what price will you have to pay for the services of a person who can enter dreams?