The titular panel refers to a (fictional) painting depicting two nobles playing chess with a woman in the background reads a book in 1471. The painting has come into art restorer Julia’s hands. As she is restoring the painting she uncovers an inscription – Quis Necavit Equitem, or, who killed the knight. Julia brings her old caregiver, Cesar, to help her solve the mystery. Soon a murder occurs and Julia is drawn into an intricate chess game where those close to her become the pieces; it appears the murderer wants to continue the game of chess going on in the painting.
It’s a pretty good read, especially if you are into art history. The story Perez-Reverte weaves out of the figures in the painting might actually be more intriguing than the murder mystery. The two nobles, a duke and his knight, are both in love with the woman in the background, the duke’s wife. Later, the knight is murdered. Was it due to the Duke’s jealousy or the knight’s ties to France?