Photo: Mario Perez/Courtesy of ABC

The few devoted fans of new series like Vanished and Kidnapped might grumble as these shows get yanked, but they should take solace: It could have been worse. Kidnapped could have become a Lost-size hit and been extended indefinitely. That’s the real irony this season: not that these convoluted, Lost-alike shows aren’t succeeding, but that the model they aspire to doesn’t work at all. Sure, Lost drew massive audiences in its first two years, but in its third season, it’s losing both viewers (down a third from last year) and narrative steam (who’s in the hatch with the Others and the numbers and the—oh, forget it). And for anyone who didn’t sign on from the beginning, there’s little incentive to catch up now. Why invest hours wading through past DVDs when your co-workers are grousing that the mysteries still haven’t paid off?

There is, however, a simple solution: Change the format, or at least reimagine it. When it so-called arc shows, we need something between a mini-series and an open-ended run. We need the TV equivalent of a novella: the limited-run show. Series driven by a central mystery (Twin Peaks, The X-Files) peter out precisely because they have indefinite life spans. The writers are forced to serve up red herrings until the shows choke on their own plot twists. (Whereas 24 works because it’s more cliff-hanger than puzzle—though Jack Bauer is surely the unluckiest man alive.)

Now let’s imagine an alternate reality in which, say, Lost was designed to run for only two seasons. Rather than getting an increasingly tedious shaggy-dog story, we’d get 48 episodes of tightly plotted, expertly interwoven suspense. Viewers would be both more willing to sign on at the beginning (knowing their investment will pay off) and more inclined to buy DVDs later (either as catch-up for newbies or as a satisfying boxed set). Sure, the show won’t syndicate well, but shows like Lost don’t syndicate well anyway. And the series finale would be huge—the kind of event TV network executives drool over. Obviously, this approach isn’t right for every show. Stand-alone dramas (CSI) and cyclical sitcoms (Two and a Half Men) can still run open-ended. And, granted, no network will be eager to pull a massive hit after its allotted two-year run. But which would you rather tune in to next fall: a brand-new mystery from the creators of Lost, that entirely satisfying and thrilling limited-run series you loved? Or yet another season of Lost, that show that started out so well but is now meandering all over the damn place? Puzzles are meant to be solved, not prolonged. You can only tease viewers so long before they feel like they’re being mocked.