What haunts us? What can't we let go of? A tennis prodigy collapses after his wins, crediting them to an invisible, not entirely benevolent presence. A series of ghosts appear at their former bedsides, some distraught, some fascinated, to witness their unfamiliar occupants. A woman returns from a visit to Alcatraz with an uncomfortable feeling. The spirit of a prisoner has attached himself to you, a friend tells her. He sensed the empathy you had for those men. In more than two dozen stories and vignettes accompanied by an evocative curiosity cabinet of artifacts and images —found photographs, original paintings, Instagram-style portraits — Guestbook beckons us through the glimmering, unsettling evidence that marks our paths through life.