“I love you, Petra’s creation!” - four friends cannot help but exclaim after the poet, admiring the beauties of St. Petersburg on vacation. And everything would be just wonderful, but the guys are haunted by the strange behavior of their unpleasant hotel neighbor. And how can you give up on this guy when, in the remote corners of an ancient park, for some reason he is picking at the ground with his foot and tying trees with fishing line, and behind his door mysterious voices are repeating some kind of abracadabra? “Who is he: crazy? Treasure hunter?! Spy?!!" - friends rack their brains, and one day late at night...