The paradoxical possibilities of physics and the shifting nature of truth occupy Detective Superintendent Richard Jury in his 20th mystery, which picks up right where the previous installment, THE WINDS OF CHANGE, left off. While drinking at a wine bar, Jury falls easily into conversation with a congenial stranger, physicist Harry Johnson, who tells him an odd story. It seems that the wife, son, and dog of his friend Hugh Gault inexplicably vanished without a trace while house-hunting--although the dog returned several months later. Meanwhile, despair and a fixed belief that his wife and child would soon reappear drove Gault into a private mental institution. Intrigued by the tale and by Johnson himself, Jury develops a deeper relationship with the man, collecting details of the case, and gradually realizes that the facts of the matter dont quite match Johnsons account.