At best, One for the Money would make a decent made-for-TV movie. This misguided clunker starring a miscast Katherine Heigl betrays its source material, the bestselling series of books by Janet Evanovich. Instead of a tough and goofy heroine, we get a smart woman acting dumb. Even the plot sags in the middle.

Starring: Katherine Heigl, Jason O'Mara and Daniel Sunjata

Rating: Two stars out of five

You know how sometimes you rate a new movie's worth by saying, "Oh, it's a rental," and they know exactly what you mean? Well, One for the Money is not a rental. At best, it's a made-for-TV movie. I can say this with some authority, not because I watch a lot of small- and big-screen mystery series (although I do), but because I've read all 18 of Janet Evanovich's numerically titled books, the bestselling source material for this misguided clunker. They may not be John le Carre, but Evanovich's comedy, romance and mystery hybrids (dubbed "comedy thrillers") are very entertaining and pretty addictive, thanks to her main creation, Stephanie Plum.

My name is Nathalie, and I'm a Plum-oholic.

In an interview several years ago, Evanovich explained the original inspiration for Stephanie and her nemesis-paramour, local cop Joe Morelli: the love/hate relationship between Bruce Willis and Cybill Shepherd in the 1980s Moonlighting series. For perennially flat-broke and less than competent Stephanie, her love life is just part of the adventure.

In this movie, however, Katherine Heigl and Jason O'Mara, who plays Morelli, have so little chemistry -- sparring, sexual or otherwise -- you don't much care whether they end up loving or hating eachother.

The weakest link is Heigl as Stephanie, the failed Macy's-lingerie sales clerk turned rookie bounty hunter. Instead of our beloved Calamity Plum, we get a smart woman simply playing dumb. (Cue the widened eyes and improbable helplessness -- about two dozen times). On the contrary, while the novel's character is well-intentioned with occasional bad judgment and worse luck, she's certainly not dumb.

Even if she's game for an extended scene involving a shower, nudity and handcuffs (and valiantly tries to muffle her Connecticut accent with a Jersey one) Heigl just isn't right. She's like casting Jennifer Garner as Miss Marple instead of Helen Mirren or Judi Dench.

Stephanie is tough and sweet, but also raunchy with a side of goofy. For me, Whitney Cummings would have fit the bill, and Emma Stone would have been ideal. In one interview, Evanovich said she thought Sandra Bullock would have been perfect for the role, in the decade before development on the project lagged and she gave up on a feature film ever being made (Bullock is 47 now; in the books, Stephanie is forever 32.) "She'll be on oxygen (and) in a walker by the time they get around to making it!" Evanovich joked, before adding that she was now thinking of Anne Hathaway. "She has a gawky Steph way about her," Evanovich said. That was 2007, and, evidently, a lot changed in the interim.

Otherwise, the casting is pretty good: Debbie Reynolds as the doddering but sassy Grandma Mazur; a motor-mouthed, neurotic Patrick Fischler as Stephanie's bail-bondsman cousin Vinnie; and Sherri Shepherd is spot-on as Lula, the retired hooker who becomes Stephanie's sidekick.

What to say about the so-called action? "If an editor tells you your middle sags, that doesn't necessarily mean that he's bored," Evanovich writes in another of her books, How I Write: Secrets of a Bestselling Author. "It may just mean that the story isn't as intense or powerful in the middle as it is in the beginning and the end."

Even if Heigl weren't woefully miscast, the rest of this feels saggy, too small (down to the bass-guitar line riffing in the background in pretty much every scene) and too feeble for the big screen. In fact, the saggy middle could be much improved by commercials playing every eight minutes. Although One for the Money was such a disappointment, I'm really hoping there won't be a Two for this show.