In Jakunówka one funeral after the other is held. The unknown plague is killing the villagers. The ones still alive are afraid of the return of the souls of the dead. What is even more terrifying – the bodies disappear from the graves.
The frightened villagers hear weird sounds coming from the nearby island. At night, they see a flickering on it. According to Szelakowa, a monster expert, there is a devil’s friend living there. It is similar in appearance to a man. In order to gain wisdom, glory, and immortality, it is ready to devour twelve cold human hearts. And so, it ventures to the graveyard at night, taking the dead back to its island hideout. The people of Jakunówka know that the monster must be dealt with. The matter is urgent: there are already eleven empty graves in the cemetery.
Marcin Konopka, the bravest of the locals, decides to face Evil. He wants to fight like an honourable villager should, with a pitchfork. So, he takes a boat to the island and attacks the Heart devourer stabbing him in the back. The monster’s life pours out of it. It will not devour the twelfth heart and will not gain the devil’s power. Despite the villagers’ questions about what happened on the island, Konopka remains silent.

“People have too many problems on the earthly vale, so from the spirits they want only peace.“
Jadwiga Tressenberg, „Mazurskie opowieści”