Renowned psychologist Joseph O'Loughlin has it all -- a thriving practice, a devoted, beautiful, fiercely intelligent wife, and a lovely young daughter. But when he's diagnosed with Parkinson's, O'Loughlin begins to dread the way his exceptional mind has been shackled to a failing body, and the cracks in his perfect existence start to show.

At first, O'Loughlin is delighted to be called in to a high-profile murder investigation, hoping his extraordinary abilities at perception will help bring a killer to justice. But when O'Loughlin recognizes the victim as one of his former patients, an emotionally disturbed young woman who nearly brought ruin upon him, O'Loughlin hesitates -- a fateful decision that soon places O'Loughlin at the top of the lists of both a bullish detective and a diabolical killer.