What has happened to Jon Manchip White? Some years ago he wrote a series of fanciful, fast-paced, and readable thrillers--like Nightclimber and The Graden Game. But this new, tiny book is a great disappointment: a wordy, pretentious reworking of a psychic/dream premise that's been used before by dozens of parapsychology-oriented writers. White's narrator is theatrical director Robert Carver, who's to hearsing in N.Y. when he gets an urgent call from old friend Dr. Paul Harkiss; Paul, who now runs The Harkiss Clinic for Oneiric Disorders (sleeping, dreaming), long ago discovered that Robert and his wife Helen are ""dream virtuosi""--and while Robert has broken away to develop his career, Helen has stayed with Paul to serve as a guinea pig in his dream experiments. So what, wonders Robert as he drives upstate to the Clinic, has happened to Helen--and why does Paul need Robert now so badly? Well, it turns out that Helen has ""found a technique of penetrating someone else's dream""--and Paul has been using her in an attempt to help super-tycoon Cornelius Van Den Bruck, who's plagued by dreams he can't remember. But the brain-electrode hookup has gone too far, so now Helen (as she lies sleeping near Van Den Bruck) is stuck in the tycoon's dream. And: ""I want you to go in there, Robert. . . . To follow her. To get her out."" This is perhaps a workable starting-point for an ESP-ish novel--with some genuine chill in the trapped-in-a-dream idea. But White merely stretches out that one thin notion--primarily with long dream descriptions--and the result is slow and soggy.