Forty-one years ago, the renowned physicist Dr. Christopher Robin vanished. Before his disappearance, his fringe science theories about the existence of endless alternate universes had earned him both admirers and enemies.

Now his widow has died and Alex Benedict has been asked to handle the auction of the physicist’s artifacts—leading the public to once again speculate on the mystery surrounding Robin’s disappearance. Did he finally find the door between parallel universes that he had long sought?

Intrigued, Benedict and Chase Kolpath embark on their own investigation as they follow the missing man’s trail into the unknown to uncover the truth—a truth people are willing to kill to protect…