Deadfall — Sarah Stegall

Private investigator Claire Turnbull meets the ghost of Old West lawman Wyatt Earp over a cooling corpse in San Francisco, and is dismayed to discover that only she can see or hear him. Reluctantly, she teams with the ghost to solve a murder mystery that threatens her own life: who killed a bigamous thief and stole a 150-year-old ship's log? Was it just another in a long string of cons, or is there really a hoard of gold hidden in San Francisco? The hunt takes Claire and Wyatt from the high rises of the modern city into a murky past buried under San Francisco.