Subtraction

Las Vegas in the 60s. Mark Paris is pretty much an ex. Ex-boxer, ex-soldier, ex-mathematician, ex-husband. Now he passes the time winning small in casinos and offering assistance to people who can't find it anywhere else. He calls himself The Professor, much to the amusement of local criminals and barmen, and the contempt of the police. An early phone-call from an acquaintance brings him his latest job, cleaning up after a sudden death, and at much the same time he's invited to help an elegant businesswoman with big trouble on her hands. Can The Professor work out the right directions to head in, before his past catches up with him, or the people who wish him ill manage to cut his equation off permanently?