Although its poor box-office performance took the luster off Kevin Williamson's storied career, the big-name screenwriter's directorial debut is actually a highly watchable piece of teen exploitation -- that is, until it runs out of ideas at its climax. Like all Williamson projects, Teaching Mrs. Tingle wears its influences on its sleeve -- plot straight out of Nine to Five, teen dynamics from the John Hughes playbook -- but that doesn't make it any less entertaining. The casting's great, although with the exception of Jeffrey Tambor, the supporting cast gets short shrift in the editing room; Lesley Ann Warren and Vivica A. Fox have almost nothing to do, while Hughes vet Molly Ringwald gets only a few wickedly funny throwaway lines. Still, Katie Holmes and Marisa Coughlan, both participants in Williamson's TV projects, make an appealing combo as the best friends who kidnap their teacher; Holmes gets top billing as the sweet, determined, underprivileged Leigh Ann, while Coughlan gets the best scenes as Jo Lynn, the aspiring actress who does Linda Blair impressions in her spare time. Barry Watson, another TV vet, seems like he wants to play edgy Judd Nelson to Holmes' wholesome Ringwald and Coughlan's oddball Ally Sheedy, but his pretty-boy character's really only there to provoke sexual rivalry. In fact, the potential of sex to destroy people's dreams is the film's major theme, and Helen Mirren does an exquisite job of embodying the curdled expectations of promising youth left to rot in a stew of romantic disillusion. As the titular teacher, Mirren spews venom and pretension like many a real-life victim of Sinclair Lewis' "village virus." She's the bitter person we've all left behind on our way out of nowhere, and it's Williamson's canny exploration of her character that provides the script with its bite. It's too bad, then, that things fall apart at the end, for until its soggy climax, Teaching Mrs. Tingle has laughs and subtext aplenty.