Named an ALA Best Book for Young Adults, Cat's story has been continued by Hugo-award winning and international best-selling author Joan D. Vinge with the very popular Catspaw and Dreamfall. Now, 25 years later, this special anniversary edition of Psion contains a new introduction by the author and "Psiren," a story never before included in any trade edition of Psion. This tough, gritty tale of an outsider whose only chance for redemption is as an undercover agent for an interstellar government that by turns punishes and helps him, is as fresh and powerful today as it was in 1982.