Dear Mr. Munson: What a bright idea: an epistolary thriller, telling through letters, faxes, E-mail, phone messages, etc., how a TV anchorwoman is stalked by a homicidal fan self-dubbed ``The Watcher.'' And so timely, too, with the epistolary Griffin & Sabine cruising bestseller lists. But what a shame that, beneath the packaging, the substance of your tale--unlike that of your Nothing Human (1991)--is only yesterday's mail. The story starts promisingly: A fax from talent agent Dan Saturn to client Joan Carpenter, telling her that his meeting with the chief of St. Louis's KMIS-TV went well; a memo from the KMIS chief to the station's news head, alerting him that Joan's a good bet to coanchor the 20/20-styled show Nightbeat; a phone message from Joan to Dan asking him to ``get me that job!'' It's fun to read these word-bites--nicely varied in length, voice, and tone-- and to watch the novel assemble like a jigsaw puzzle. We're glad when Joan gets the job; we feel for her when ratings sag because the news head treats her like a bimbo; we worry when she gets her first, sexually tinged letter from The Watcher. Modest suspense is generated as The Watcher's letters and then actions turn ominous, as he--or she?--sends the ratings soaring by first castrating a critic who panned Nightbeat, then by killing Joan's coanchor. But this all comes to little: The premise of a crazed fan, nothing new (cf. Bob Randall's The Fan, 1977), wears thin, and, though several suspects are perfunctorily set up--a gardener; two of Joan's suitors; a real-estate agent--there's no surprise when, in a flat scene, The Watcher is finally revealed, since one suspect is as good as the next. Overall, then, better in premise than in delivery. We like the chances you've taken with form, though, and we wish you success with your next and awaited novel.