Here, Rosen strays from the playing field (Strike Three You're Dead, etc.) and comes up with a less-than-compelling score. Harvey Blissberg, ex-baseball pro, now a Boston P.I., has been hired by TV-producer Roy Ganz to baby-sit Harvey's old roommate, Met star Dave Kasick--who's to guest-host Ganz's live late-night Last Laughs and is trying to deaden his stage fright with alcohol. Ganz, once the child star of My Little Brother, is trying to re-create the glory years of Last Laughs in the 70's. It's not easy. His roster of comedy writers--old-timers Leo Rhoades and Marty Beaver; 40-ish Dickie Nacke; neophytes Causey and Vergaard; lone female Karen Baldwin, and others--tolerate Ganz's acerbity, and strive mightily, producing plenty of shock value but little laughter. Meanwhile, the show goes on. Dave performs respectably. Later, the after-performance party is winding down when Ganz's body is discovered--he jumped, fell, or was pushed from his office window. Of course, the network wants Harvey to find answers, and he works hard at it, questioning everyone even remotely connected with the show. Eventually, he finds an important clue, but not until he's explored Ganz's boyhood years and talked to retired director Max Wiley, as well as to Ganz's half-senile mother, does it fall into place, in a tense denouement. Though there's too much early groundwork here (with too many dull ""funny"" men), Harvey manages to retain his laid-back charm; the author his sharply attuned eye and ear; and, happily, the pace quickens as the plot thickens--to produce engrossing entertainment just below the high standard set by Rosen's previous work.