With their sun about to go nova, the people of Epictetus III face annihilation. The Enterprise has come to lead the rescue operation, but there is no way to evacuate a population of over twenty million, leaving Picard to make an agonizing decision.
When an abandoned space habitat is found within a distant asteroid belt, the Starship Enterprise is sent to investigate. Captain Kirk and his crew discover an artificial world full of technological marvels - and unexpected dangers. But wonder and curiosity give way to fear when the habitat's shifting orbit sends it on a collision course with an inhabited planet within the same solar system.
The Hawking left Earth during the 21st Century on a one-way mission to colonize a distant world. Due to the relativistic effects of pre-warp travel, it's crew has aged only thirty years while two centuries have passed outside the ship. When the Starship Enterprise comes to the rescue of the malfunctioning Hawking, the colonists find themselves thrust into a universe and an era that has left them behind.
Apparently rehabilited from the insanity that resulted from the Antosians' treatment of his horrific injuries, Captain Garth returns to active duty, assigned to mediate a crisis on Antos IV with the help of Captain Kirk and the crew of the Enterprise, but Kirk begins to worry that Garth has renewed his plans for conquest.