Sudden Mischief by Robert B. Parker

When Susan's ex-husband, Brad, appears after a decades-long absence, nearly broke and the object of a sexual-harassment suit, Spenser reluctantly agrees to help. As he investigates the circumstances surrounding the suit, he discovers that fund-raiser Brad is swimming in very deep water: mobsters, who were using his fund-raising campaigns to launder money, have discovered he was cooking the already cooked books and aren't at all pleased. The deeper Spenser digs, the more bodies he uncovers and the more culpable Brad appears to be.

Chance by Robert B. Parker

Spenser is hired out on a marital matter that entangles him with the mob. When Boston hoodlum, Julius Ventura, approaches Spenser about finding his daughter's missing husband, it's clear he's not telling them the whole truth, but Spenser nevertheless agrees to take the case.

Thin Air by Robert B. Parker

Lisa St. Claire, the pretty young wife of a middle-aged cop, Frank Belson, has disappeared. When somebody takes a shot at Frank a few days later, he asks Spenser to find her. Spenser quickly discovers that she had a past and a different identity, in the L.A. underworld of drugs and sleaze.

Walking Shadow by Robert B. Parker

Hired by the Port City Theatre Company's board to investivgate the director's claims that he is being followed, Spenser feels like a fish out of water. Then an actor is gunned down during a performance of a controversial play and Boston's premier private cop goes into action.

Paper Doll by Robert B. Parker

Hired by an aggrieved aristocrat who refuses to believe that his wife Olivia's brutal street-slaying was random violence, Spenser, the Boston private investigator, plunges into a world of grand illusion. No-one is what they seem.