D-

A thrill-free thriller is a difficult thing to manage, but Christian E. Christiansen pulls it off in this bargain-basement variant of “Single White Female,” which dredges up every cliché of the genre and then bungles each and every one of them.

The heroine is Sarah Matthews (Minka Kelly), a girl from Des Moines who comes to the University of Los Angeles to study fashion design. You can tell she’s got style because she wears a man’s hat and scarves.

Sarah’s assigned a roommate in the dorm—Rebecca (Leighton Meester), a high-strung type who quickly turns possessive. Before long Rebecca—don’t call her Becky!—has attacked Sarah’s party-girl pal Tracy (Aly Michalka) in the shower and sent her packing to another dorm; gotten her sleazy prof (Billy Zane) fired for sexual misconduct; and even killed her little kitty! Dim bulb Sarah doesn’t suspect that her roommate is crackers, even when the girl’s parents (Frances Fisher and Tomas Arana) ask her—during an odd Thanksgiving visit—whether their daughter is taking her meds. Or when, on the same trip, they encounter a terrified girl who approaches Rebecca to say, “I was never your friend.”

Maybe that’s because she’s swooning over Stephen (Cam Gingandet), the frat boy drummer she’s taken up with—when Rebecca’s not keeping them apart. Stephen’s the replacement for high-school beau Jason (Matt Lanter), who’s gone off to Brown but still calls Sarah insistently, begging her to take him back. He comes out to California to woo her in person, only to fall into Rebecca’s unforgiving clutches.

Of course, there’s a big denouement involving Sarah, Rebecca, Stephen and Sarah’s other pal, world-travelling lesbian designer Irene (Danneel Harris), who commits the unpardonable crime of inviting Sarah to move in with her.

That’s an awful lot of incident crammed into ninety minutes, and one would expect that Christiansen would push it ahead breathlessly. But instead the picture plods mercilessly. Each big moment is staged without imagination or style, and Phil Parmet’s cinematography is so dark and murky that they’d all be dull even if they were more excitingly played. And the acting is strictly amateur-night quality, with Meester chewing the scenery, Kelly seeming all too authentically dense and Gingandet delivering virtually every line with a dismissive smirk that the script might deserve, but still gets tiresome fast. Even a veteran like Zane succumbs to the prevailing mediocrity, though to be sure he’s never exactly been an epitome of subtlety. The best performance, in fact, is given by the doomed kitten, who disappears from the action much too quickly.

But the cat’s smart to get out as soon as he can. The leads aren’t so lucky. And neither is the audience.