This psychological thriller involves split brain research, animal rights, and a love quadrangle. It was originally published in hardcover by Bantam-Doubleday-Dell.
Neuropsychologist Clare Austen conducts research on the leading edge of reality. She has been intending to cease her experiments with Tommy Dabrowski before she becomes too emotionally involved with this appealing but married rock musician. Then personal considerations are swept aside by a high-voltage chain of terrifying events, which begins when Clare's mentor - the eminent Dr. Stanford Colton - is murdered in his university office. The only person to encounter the killer is Clare's most problematic experimental subject. But Tommy is a split-brain patient: only half his brain can still communicate to the outside world - and it's the other half that's a witness to murder. Clare's academic work now takes on a sharp urgency. Only by cracking Tommy's neural codes can she unlock the deadly secret trapped in the silent half of his brain.
As fresh crimes slash through the research community, the usually cautious Clare plunges into the investigation, despite threats to her life and the chief detective's severe warnings against interference in his case. Plagued by turbulent memories and unnerving suspicions, Clare must adapt her esoteric experiments to life-or-death stakes, in the wild hope of extracting a clue to the killer's elusive identity. Before she and Tommy are through, they discover great horror on that edge of reality.