Curator Naoki Yabe becomes fascinated by two paintings left by the late artist Tojoji Kei, who worked obsessively before taking his own life. Using iconography to decode their hidden meanings, Yabe is led to the truth behind a double locked-room murder that occurred on Christmas Eve twenty years earlier. This debut novel, winner of the 9th Ayukawa Tetsuya Award, incorporates paintings created by the author himself, weaving art history and detective fiction into a seamless whole.

A double locked-room secret hidden within the final works of a painter who created obsessively before ending his own life.