Oh, how Romka and Leshka didn’t want to languish in Voronezh during the entire autumn holidays. But as soon as the friend’s grandmother read the yellowed letter to them, Romka’s eyes lit up. It's no joke: there's a treasure hidden in one of the old town houses! It’s just a matter of little things—in a matter of days, you can find something that has been hidden from human eyes for more than half a century. “Forward, for treasures!” - Romka decides, and the brother and sister set off. Strange events begin to happen while still on the train. In the empty carriage, a real... vampire appears in front of Leshka.