Blood Type. John Marshall Tanner Investigation 8

Tom Crandall - war hero, social crusader and P. I. John Marshall Tanner's close friend - is discovered dead in an alley in San Francisco's sleazy Tenderloin district. The police call it suicide. But a cryptic answerphone message leads Tanner to suspect that Clarissa Crandall's affair with millionaire Richard Sands may have sealed her husband's fate. As he investigates his friend's death, Tanner turns up suspicious clues that lead to the city's vulnerable blood supply and to Tom's homeless, schizophrenic brother, whose chilling conspiracy theories are closer to the truth than Tanner could ever have imagined.