An U.S. Spaceship lands on a desolate planet, stranding astronaut Taylor in a world dominated by apes, 2000 years into the future, who use a primitive race of humans for experimentation and sport. Soon Taylor finds himself among the hunted, his life in the hands of a benevolent chimpanzee scientist.

Rose Loomis and her older, gloomier husband, George, are vacationing at a cabin in Niagara Falls, N.Y. The couple befriend Polly and Ray Cutler, who are honeymooning in the area. Polly begins to suspect that something is amiss between Rose and George, and her suspicions grow when she sees Rose in the arms of another man. While Ray initially thinks Polly is overreacting, things between George and Rose soon take a shockingly dark turn.