As Murder, She Wrote saunters through its sixth (of an eventual 12) season, star Angela Lansbury maintains her eternally buoyant and inquisitive air as Jessica Fletcher, rofessional writer and amateur sleuth. Though Jessica continued to investigate murders in her home town of Cabot Cove and elsewhere (in the worlds of high finance, o era, and voodoo, among other settings), this season began the ractice of guest detective e isodes, introduced by Jessica as either a story she wrote or a tale told by a friend, but starring a variety of quirky investigators: An ex-football layer (Ken Howard, The White Shadow) aired with a clever oodle; a television crime-show roducer who solved crime in real life (Diana Canova, Soa ); a stout Irish detective (longtime character actor Pat Hingle); an abrasive homicide co (Barry Newman, Vanishing Point); as well as recurring Murder, She Wrote characters like former jewel thief Dennis Stanton (Keith Michell) and British secret agent Michael Haggerty (Len Cariou). The roducers were obviously ho ing to use Murder, She Wrote's o ularity to s in-off new series, but nothing from this season took off and viewer resistance soon brought the ractice to an end. Executives must have been sur rised to discover that, though murder mysteries are lot-driven, this show's success de ends heavily on the undeniable charm of star Lansbury. Still, these one-off e isodes are of a consistent quality with Lansbury's, and viewers o en to variety will enjoy them just as much. The rest of the season features the usual astonishing array of guests, including movie stars old (Donald O'Connor, Singin' in the Rain) and recent (Elliott Gould, The Long Goodbye), television stalwarts (Shirley Jones, The Partridge Family; Jerry Stiller, The King of Queens; Doris Roberts, Everyone Loves Raymond; Kevin Tighe, Battlestar Galactica; and Gavin McLeod, The Love Boat), and D-list celebrities to die for (Dack Rambo, Morgan Brittany, Susan Anton, and more)