Darkover #12 - The Forbidden Tower

This is the novel of four who defied the powers of the matrix guardians - fanatics who protected those powers so that the planet of the ruddy sun might never fall beneath the influence of materialistic Terrans.

The four who found themselves fused into a terrifying unity in that defiance were two men and two women.

The men were Damon Ridenow, a Gomyn of the ruling caste, and Andrew Garr, the Earthman who had won for himself the right of clan-entry.

The women were Ellemir, betrothed of Damon, and Callista, who foreswore her vows to seek the love of the alien from the stars.