A shuttle crash strands Kirk's party with a reclusive scientist and a luminous entity that loves him.
A shuttle carrying Kirk, Spock, McCoy and a seriously ill diplomat is captured by a cloud of energy, the Companion, on a small planet where they meet Zefram Cochrane, the inventor of warp drive, who has lived there for many years. The Companion has kept him alive because it loves him.
The story provides the history of Cochrane, who becomes a major figure in the Trek universe. The unusual love story between a human and a being of energy gives it emotional weight. It is remembered for its gentle resolution.