As the villagers of Three Pines prepare for a special celebration, Armand Gamache and Jean-Guy Beauvoir find themselves increasingly worried. A young man and woman have reappeared after many years. The two were young children when their mother was murdered. Gamache and Beauvoir’s memories of that tragic case come rushing back. As Gamache works to uncover answers, a letter written by a long dead stone mason is discovered. In it, the man describes his terror when bricking up an attic room somewhere in the village. As the bricks are removed, Gamache, Beauvoir and the villagers discover a world of curiosities. But the head of homicide soon realises there’s more in that room than meets the eye. In unsealing that room, an old enemy is released into their world. Into their lives. And into the very heart of Armand Gamache’s home.