Darkover

Nobody alive knew how the feud between Storn and Hammerfell had begun, but that didn't stop the fighting. When Storn's men burned Hammerfell's castle, his infant twin sons were separated, and each grew up thinking himself the rightful Duke of Hammerfell. Conn, raised in the mountains by his father's paxman, continued to fight the Storns. Alastair grew up with his mother in Thendara and planned to marry his cousin, Floria. But when Conn came to Thendara to seek King Aiden's help, and the twins encountered each other, it changed all their lives.

Leonie Hastur has a high degree of laran, the telepathic power of the Comyn caste, and wants to be Keeper of Arilinn Tower, which will give her as much power as her twin brother Lorill, Heir to Hastur. But she has a premonition that something strange and disturbing will come from the sky and change their world forever. She is correct. Ysaye Barnett loves life on shipboard and would happily stay right there, with her beloved computers, forever.