Hamnescher, a small island west of Marstrand, was bustling with activity. There were two months left before the opening of the Pater Noster lighthouse after a long restoration. Workers were diligently repairing a dilapidated wall in a storage room when it suddenly collapsed. Apparently, the ancient stones were no longer able to bear the weight of the secrets that they had kept for so long. Behind the ruins, the eyes of the Polish workers saw a room that once belonged to the family of the lighthouse keeper. And in the twilight they saw the dead man. The dead man was sitting facing them, as if he had been waiting for guests for a long time... Karin Adler from the Gothenburg criminal police takes up the investigation. But who is this mysterious man from the past? And why was he walled up?