Long-suffering police detective Peter Diamond investigates a series of strange occurrences on the set of a television series, Swift. An elderly actress suffers a heart attack after encountering a masked intruder in her home. When cameraman Greg Deans goes missing, a widely loathed local vagrant falls under suspicion. Diamond's desperation to find the culprit is exacerbated by his boss, Georgina, who's nudging him into early retirement. A fleet-footed whodunit, Showstopper is artfully plotted, with enough morbid humor to keep the proceedings from becoming grim. (BH)