Star Trek: The Original Series: The Joy Machine

Timshel was once the vacation spot of the galaxy, full of culture, natural
beauty, and friendly, hospitable inhabitants. But now Timshel has cut itself
off from the universe. No one is allowed to enter or leave. Concerned, the
Federation has sent agents to investigate, but none have returned.

Captain Kirk and the crew of the Starship Enterprise^TM are shocked to discover the truth: the people of
Timshel have succumbed to an insidious new technology that guarantees every
citizen total pleasure, a soul-destroying ecstasy that has enslaved their
entire civilization. Kirk and Spock have faced many threats before, but now they face the most seductive menace of all: perfect happiness. And the rest of the Federation may soon fall under the irresistible control of the Joy Machine.