You are a cook, a perfectly rational agent. Having recently cooked a lovely snack for the group who was chosen by the mechanism, you are pleased with your work. The Chef enters your kitchen and informs you of a conundrum he is facing. During the last experiment, he by accident seems to have placed his favorite bookmark into one of the tomes distributed to the participants in the last experiment. However, he has no idea which participant it might be. You know that all participants have carried their book with them as they were nicely asked. What is your credence that the Chef will find his bookmark in the dining hall, where the chosen participants are eating their scrumptious dessert?