 A mysterious signal from an unexplored planet somehow mesmerizes the male crew members into daydreaming of fantasy women. The women crew members are unaffected, though. Following the signal, Kirk beams down with an all-male landing party and is quickly subdued. Awakening, the landing party find themselves with headbands on that are siphoning off their life force, making them age quickly. They discover that the long-lived and all-female residents of the planet obtain their long life and beauty by luring male spacefarers and draining their life force. The weakened landing party manages to escape and hide from their captors in a hollow sculpture. Meanwhile, Uhura has taken command of the Enterprise, seeing that the men have become completely useless, constantly daydreaming. She assembles another landing party (all-female) to rescue the first. They win a battle over the female inhabitants, who are willing to release Kirk and his party, but they don t know where they are. Using a locater device, they see that the men are about to drown in the sculpture, which is filling with water from a rainstorm. The women run out to the courtyard and shoot the sculpture and freeing the men. The men s life force is then restored, bringing them back to their more youthful appearance.