Secret Rendezvous

From the moment that an ambulance appears in the middle of the night to take his wife, who protests that she is perfectly healthy, her bewildered husband realizes that things are not as they should be. His covert explorations reveal that the enormous hospital she was taken to is home to a network of constant surveillance, outlandish sex experiments, and an array of very odd and even violent characters. Within a few days, though no closer to finding his wife, the unnamed narrator finds himself appointed the hospital's chief of security, reporting to a man who thinks he's a horse.