The book opens with the Enterprise in pursuit of a spaceship; a notorious pirate, Aux Rex. The chase continues to the planet known as Sanctuary - a world run by a race of androgynous beings, called Senites, who welcome criminals, pirates and all fugitives, providing them sanctuary from their persecutors, and see to their every needs. Sanctuary is also completely protected by a planetary shield that blocks transporters, weapons and communications from between the surface and space. Captain Kirk, mister Spock and Dr. McCoy continue the pursuit of the pirate ship in a shuttlecraft as it makes its last ditch escape and enters the atmosphere which soon ends with the ship crashing into a mountain. The shuttle team land and look for possible survivors, having detected that two people had ejected, but find none, but more worrying is that their phasers, tricorders and communicators have also stopped working. The three return to where they landed the shuttle-but find it has vanished without a trace. Unable to contact or get back to the Enterprise, they realize that a journey onto Sanctuary is a one-way trip, and no one ever escapes. The Enterprise trio seek to find a way of escaping, and all without the use of technology, they embark on a grueling journey trekking on foot, swimming and even rowing through Sanctuary's wilderness, and towns populated by all manners of species. Meanwhile on the Enterprise, Scotty is left to deal with trying to locate the missing officers, the uncooperative senites, and resisting the charms of an ex Orion slave girl,one of many bounty hunter ships also in orbit, poised to capture anything trying to enter or leave Sanctuary. Down on the surface, Kirk, Spock and McCoy discover the chilling secrets of the senites and what they do to their 'guests'- i won't spoil it here - might not be the most compelling of stories, but this book is generally well written, easy going read, and has plenty of action that keeps you interested, oh, and the method of which they do make their eventual escape is certainly interesting to say the least.