The death of a 16-year-old, dressed as an ‘Immortal Knight’ and having taken a fatal overdose, proves a perplexing case in the ancient city of Tours. Juge d’instruction Matthieu Lombard is brought in to lead the investigation. When the adolescent’s death is followed a few weeks later by the gruesome murder of a firebrand author, Lombard senses a malign coercive force behind the two fatalities, one that succeeds in challenging his own loyalties and assumptions.

What is it that is nagging at Lombard, locked away in the past? What soon becomes clear is that this game is beyond roleplay. It is deadly.