A special crossover collaboration between Spy X Family and Kamaitachi no Yoru, which adapts the events of Chapter 94 into a Sound Novel style reminiscent of the original game.

During a ski trip, the Forgers take refuge within a ski lodge alongside 6 other guests and 3 employees. Suddenly, one of the guests is found stabbed in the back, and suspicion quickly falls on the only person without an alibi: Yor Forger.