TAS Season 1 Episode 4 The Lorelei Signal

Plot

The Federation starship Enterprise investigates a sector of space where starships have been disappearing every 27.346 years. A compelling musical signal lures the Enterprise to a remote planet in the Taurean system. The music works on the men of the Enterprise, affecting their judgement and causing them to experience euphoric hallucinations. Captain Kirk, First Officer Spock, Chief Medical Officer Dr. McCoy, and Lieutenant Carver beam down to the source of the signals. The inhabitants are a race of beautiful women who want to celebrate their arrival. As they indulge in the entertainments the women offer, they find themselves in a lethargic state and rapidly aging. Headbands locked around their foreheads transmit their life-force to the women, who are growing in strength.
On board the Enterprise, Communications Officer Lt. Uhura talks with Nurse Chapel about the men's condition and concludes that she must take command due to the euphoric state of Chief Engineer Scott.
Kirk and his party gather enough strength to escape to a spacious garden and hide inside a tall urn. They realize the pace of their loss of strength correlates with the proximity of the women. Spock, who has not aged as much due to longer Vulcan longevity, agrees to go back to retrieve their communicators; he tells Uhura to send an all-female rescue party.
Uhura beams down with Chapel and a female security force. When the native women try to force them to leave, they stun them with their phasers. When Uhura threatens to destroy their temple, the Taurean women explain how they came to be in their current situation; when their people settled on the planet, the planet weakened them, and the women could only survive by draining the men's remaining energy, causing their deaths. The women are now immortal and unaging, but cannot reproduce, and every 27 years must lure males and drain their life forces to stay alive. At Uhura's urging, the Taurean women help them locate the male landing party, who are drowning in the urn due to a rainstorm. The female landing party frees them using their phasers.
The aging process is stopped with the removal of the headbands, but they cannot find a treatment to restore their original age. Spock comes up with the idea of using their original transporter patterns from when they first beamed down.
Uhura returns to the planet, and witnesses the Taurean leader, Theela, destroying the device that had been luring starships, stating that Uhura should tell Kirk she kept her side of the bargain. Uhura informs them that a ship of women will return to bring them to a habitable world and that the women's bodies should return to normal in a few months. Theela is pleased, preferring a life fully lived to a static immortality.