When two award-winning science-fiction masters like Anne McCaffrey and Elizabeth Ann Scarborough collaborate, the results are astonishing. Their master creation is Petaybee, a sentient planet able to guide its own evolution and, with some help from its loyal inhabitants, defend itself against predation by offworlders. Now, at last, McCaffrey and Scarborough return to Petaybee for the thrilling conclusion of the Twins of Petaybee trilogy, the sixth...