With her agency going great guns, Sharon McCone is known as one of the best detectives in the business...until her reputation is threatened by an imposter. The woman's resemblance to McCone is uncanny. Her knowledge of McCone's life is chilling. And with her lover Hy Ripinsky away on business, McCone is alone as the double insidiously sabotages McCone's career, invades her home, and leads her into a deadly game of cat and mouse through San Francisco's underworld. Now, with professional detachment giving way to blinding rage, McCone is fighting for her life. But her very essence is also at stake...as a hunger for personal justice overrides her fiercely held ethics and lets loose a primeval urge for revenge.