First a rock star is killed while taping the Toni Tennille show; then an ex-athlete singing-star keels over on Johnny Carson; then talk-show groupie Mabelle Merriwether gets a hatpin through her medulla oblongata while sitting in the Phil Donohue studio audience. And so it goes--in this talky, half-serious mystery by talk-show pioneer Allen, who himself pops up every now and then to narrate (distractingly) in the first-person. Most of the story, however, is delivered from the viewpoint of Hollywood shamus Roger Dale, a not-very-engaging know-it-all who endeavors to solve the murders. The motive? Apparently vendetta on show-biz types with loose morals. The suspects? The victims' agent; the victims' psychologist (who himself turns up dead); a Rex-Reed-y TV critic; a mobster. The clues? Notes and tapes sent by the taunting killer to detective Roger. So finally the unstartling culprit is revealed on a climactic talk show, of course--with all the suspects and all the talk-show hosts on the air together; and, throughout, Allen drops in celebrities whenever possible. But these cameos are disappointingly bland, the on-the-air banter is surprisingly unconvincing, and Allen's relentless punning (which is funny when he does it aloud on TV) is mostly tedious on the page. Pretty much for TV-celebrity watches only, then; others will prefer the TV-background mysteries of Simon Brett and William De Andrea.