Transplanted New York cop Dave, now chief investigator for Public Defender Anne Swenson in Mesa Grande, Colorado, has hired young Roger Meyer (Mom Meets Her Maker) to assist him. Roger is in the cast of Macbeth, being produced by the town's amateur theater group, and is on the scene when one-time Hollywood actor-director Martin Osborn is stabbed to death on stage during the opening performance. Vivacious, promiscuous Sally Michaels, playing Lady Macbeth and recently discarded by Osborn, is charged with the crime and is to be defended by Swenson. But Dave's mom, who solves all his cases, isn't satisfied. By the time she's guided him through a dozen other possibilities to a reenactment of the scene, another cast member has been killed and several false statements uncovered. The denouement is relentlessly overdrawn; motivation for the killer's elaborate, reckless plan seems absurdly feeble; the split narration, alternating between Dave and Roger, is no help, and Mom's getting to be a downright bore.