Andrew is a Terranan. While in Thendara he saw a ghost girl. He ended up staying on Darkover and joined Mapping and Exploring. The plane he is on crashes in the Kilghard Hills. while trying to get supplies from the damaged plane, Andrew finds out he is the only survivor. He's about to enter the damaged plane when the same lady he saw in Thendara keeps him from entering the plane again just before it falls off the cliff.
Later, the ghost lady who turns out to be a captured keeper named Callista helps him find a place to get out of the weather. Andrew ends up finding Armida, the Alton stronghold. When he sees Ellemir he thinks hes seeing Callista. When Ellemir and her relative Damon Ridenow finds out he can see Callista when they can't, Even Leonie Hastur current Arillin keeper cant find Callista.
Callista had been taken from Armida, they do find her matrix stone. From the description they think Callista is being held in the Caves of Coresanti. Dom Esteban Lanart, the father of the twins, shows up, he has been injured by the Catmen and is paralyzed. Damon is not much of a swordsman but Esteban, the current head of the Guards, is. Using a matrix stone placed on Esteban's sword, Damon ends up rescuing Callista and she and Andrew end up becoming freemates.