Once again blood has flowed down the mountain slopes. At the height of the tourist season, the body of an elderly man is found on Rysy, and the perpetrator's modus operandi leads to only one conclusion: the one everyone feared has returned. Besides the coin in his mouth, a bloody inscription has been cut into the skin of the victim's bare chest: 'Revertar ad Ierusalem in misericordiis'. The situation is complicated by the fact that the victim was placed right in the middle of a border post, so both the Poles and the Slovaks intend to lead the investigation. Panic breaks out in the town and on the trails, while Wiktor Forst wakes up in a hospital in Zakopane. He does not remember what happened to him after he left Poland to check what was inside a certain post office box… No fire burns for ever. But every one leaves ashes behind.