Plot summary
Andrew Carr is employed as a technician in the Empire's Mapping and Exploration survey of Cottman IV, known locally as Darkover. His survey plane encounters a storm over the mountains and crashes. Carr survives through the intervention of a diaphanous figure that he initially believes to be a ghost. She tells him her name is Callista, a Keeper, and she is communicating with him through the Overworld. Carr believes none of this, but follows her directions to shelter.
Meanwhile, on the road to Armida, Damon Ridenow discusses recent violent conflicts with a native species called the cat-men with his guardsmen. Ridenow is a matrix technician who was recently dismissed by Leonie Hastur, Keeper of Arilinn, on the grounds that he is "too sensitive."
During the journey, the group is attacked by an unseen entity. Only Damon Ridenow survives. He arrives at Armida to find that it, too, has been attacked, and Callista Lanart was kidnapped. Her twin, Ellemir Lanart, assures him Callista is alive because she can feel her sister's telepathic presence, though they cannot communicate directly.
Damon ventures into the Overworld to seek Callista, but finds only a "great darkness" and a vaguely evil presence. Meanwhile, Andrew Carr arrives at the door seeking shelter and assistance. He mistakes Ellemir for Callista. After introductions and food, Andrew describes his experiences. Damon concludes Callista is being held by the cat-men.
Ellemir's father, Esteban Lanart, Lord Alton, arrives with his guard. His party has also been attacked by an invisible enemy, and Lord Alton was gravely wounded. Damon uses his laran abilities to save one of the wounded guards, but can do nothing for Lord Alton, who is permanently paralyzed.
The next day, Lord Alton is informed of the situation, and Damon Ridenow tells him he wants to marry Ellemir. Alton approves Damon's suit, but disapproves of Andrew Carr's interest in Callista because she is a Keeper.
Damon says he will attempt to rescue Callista. Lord Alton suggests he use his Alton gift of forced rapport so that he can provide Damon with his own superior sword skills, which Damon lacks. After testing this theory and mounting a small matrix jewel in the hilt of his sword, Damon leaves for the darkening lands and the Caves of Corresanti. They engage the cat-men in several small skirmishes along the way.
At Armida, Andrew Carr has learned how to enter the Overworld, and locates Callista. Desperate to help her, he somehow manages to teleport himself into the caves. Andrew and Callista make their way through the caves with Damon and face off against the Great Cat, a larger cat with a powerful matrix jewel. The matrix is destroyed, and everyone returns to Armida.
Callista, the Keeper who is sworn to lifelong virginity, contemplates giving up her vows to be with Andrew.
