Central Park South

Mariel Hemingway had a naughty idea. At the preshow party for Central Park West, the star had just finished mugging for a mosh pit of paparazzi and feeding a buffet of sound bites to ravenous reporters. As she moved through the champagne-soaked crowd at New York City's Museum of Modern Art, she paused to share her thought. ''Maybe we should never air the show,'' she giggled. ''Just keep putting it off. I mean, the hype is so great, how can we live up to it?''

Maybe she was right.

At 9 p.m. on Wednesday, Sept. 13, America finally got a chance to glimpse the show it had been hearing about — and hearing about — all summer: Central Park West, the CBS sudser set in the big bad world of New York magazines! The show from TV's golden boy, Darren Star, the brain behind Melrose Place and Beverly Hills, 90210! The show that would save the network! THE SHOW!

There was just one problem: America didn't watch. CPW's ratings were as rotten as Madchen Amick's Carrie, the series' oversexed nightlife columnist. Despite decent reviews, it limped into fourth place in its time slot, behind ABC's Grace Under Fire and The Naked Truth, NBC's Dateline, and Star's own Fox show 90210. A bewildered CBS quickly reran the episode on Friday, hoping to hook more viewers. The show did even worse. The next Wednesday, West tanked. Valleyed. Blew.

It seems CPW could become CBS' biggest embarrassment since, well, since last season's entire prime-time performance. It could also prove to be Darren Star's first career belly flop. Is this indeed his Bitchtar? His Editors Inc.?

Star sure doesn't think so. Two days after Black Wednesday, the producer is smiling in his mammoth Manhattan office, seemingly in no need of Prozac. An underling drops off a printout of David Letterman's Thursday-night list of Top Ten Surprises in Central Park West. ''This is terrific! This is so funny!'' laughs Star, 33, pointing to No. 2: ''O.J.'s hilarious cameo as a hot dog vendor with bloody tongs.''

Call it well-earned confidence — or deep denial — but Star professes no doubts in that wundermind of his. ''I know the audience will find us,'' he says. ''I'd much rather start here and work my way up. This is familiar territory.''

He has a point. 90210's 1990 premiere lured just 10.9 million viewers — compared with CPW's 9.7 million. Melrose has traveled a bumpy road too: Its 1992 debut drew 16 million viewers, but it quickly dropped off, bottoming out at fewer than 7 million. Now those Fox soaps routinely draw twice that number.

''This genre is historically about seduction,'' says coexecutive producer David Stenn. ''You have to bring your audience in. It's not like ER — a home run out of the box.''

But you'd think it'd at least get to first base. After all, no show has ever arrived with such a PR blitzkrieg. Third-place CBS heralded CPW as its savior, the bait for a much-needed demographically correct young audience. And it went promo crazy: There were buses roaming New York covered with photos of the pouting cast. Six-page ads trumpeting the series as ''CBS' new hit drama!'' A write-in contest to win a walk-on role. A Web page on the Internet. A showing of the premiere on the Times Square Jumbo-Tron screen. ''Well, we didn't do skywriting,'' deadpans George Schweitzer, CBS' executive VP for marketing.