"It Only Takes a Moment" (Morrow. 345 pages. $24.95), by Mary Jane Clark

For Mary Jane Clark fans, the most thrilling TV network has to be KEY. The fictional company has some very nasty anchors, producers and correspondents who would do anything, even murder, to get what they want. Decent employees of the network regularly become killers' targets and must use their sleuthing talents to stay alive.

The author, a former writer and producer for CBS News, is good at dreaming up scary happenings involving KEY staffers and describing them in lucid prose and succinct chapters that do not strain the patience of TV-age readers.

Her novels are essentially like Agatha Christie's whodunits, but they have a hard, contemporary edge that enhances the fear factor. They are so addictive, in fact, that her readers would surely suffer withdrawal symptoms unless they kept coming on a regular basis.

Her latest effort, "It Only Takes a Moment," just arrived in the middle of summer, but dismayingly, it fails to provide the arctic chills her readers have come to expect.

The protagonist, or victim, is Eliza Blake, host of the top-rated KEY News morning show. Poor Eliza. Terrible things always happen to her. She was almost murdered in Clark's three previous novels, "When Day Breaks," "Do You Want to Know a Secret?" and "Close to You." Now, bad people have kidnapped her precious 7-year-old daughter, Janie, and her caretaker, Carmen Garcia.

One anonymous letter mentions Janie and asks Eliza: "Can you imagine what your life would be like without her? Janie better appreciate how lucky she is to have you, because it only takes a moment for life to change forever."

Indeed, the TV star's life changes overnight from a glamorous and fulfilling one to that of agony and fear. Her home in the peaceful suburban community of Ho-Ho-Kus, N.J., is overrun by investigating FBI agents, concerned KEY colleagues and media people waiting for news breaks. A single mother whose husband died of cancer, Eliza is frantic with the real possibility of losing Janie. In desperation, she even turns to a psychic for help.

Eliza's anguish comes through loud and clear in the novel, but suspense never builds. There are a few suspects, but they are total strangers to Eliza, and not very convincing or interesting ones at that.

The literary devices Clark so effectively used in "Nowhere to Run" and other books are AWOL: No twisted character hiding behind a friendly mask, no beguiling red herrings, no titillating hints, no soliloquies by an unidentified murderer plotting his or her next move. Clark does her usual good job with a surprise ending, but it is too little, too late.

Taken as a whole, though, her 11 novels attest that she is one of the most talented storytellers around. If she keeps on the right track, she could very well claim to be "the Queen of Suspense" one day - the title currently bestowed by some on her former mother-in-law, Mary Higgins Clark.