An impossible crime ...When forensic pathologist Evelyn James is called out to the scene of a murder, she finds the body of a beautiful, young Cleveland heiress, violently strangled and left in a life-like pose, a priceless diamond necklace carefully arranged round her neck. There is no trace of the killer's deadly visit to the penthouse crime scene. It's as though the murderer is a ghost, capable of walking between walls, untraceable - and unstoppable. As the terrified inhabitants try to go about their daily lives, the killer stalks, undetected through the corridors. When another young woman from the building is brutally attacked, Evelyn knows she must unravel the mystery of the unseen killer, before it's too late ...