Unforgettable Rosario Dawson, Katherine Heigl, Geoff Stults. Directed by Denise Di Novi. Rated R. Opens Friday citywide.

Given how much trouble Katherine Heigl has had finding a new direction for her career since leaving Grey’s Anatomy seven years ago, her go-for-broke turn in the formulaic thriller Unforgettable might open up some new possibilities for her as a supervillain in the booming comic-book adaptation market. Heigl’s Tessa is so cartoonishly evil that she’s barely even a real person, and Heigl relishes the malicious, devious role, playing a sinister ex-wife out to destroy her ex-husband’s new fiancée. Rosario Dawson doesn’t have much to work with as Julia, a straight-arrow fiction editor who moves in with hunky brewer David (Geoff Stults) and his young daughter, only to discover that David’s ex has a really hard time letting things go.

Writer Christina Hodson and director Denise Di Novi do nothing to deviate from the established formula of romantic-obsession thrillers, without the subversion of a movie like Joel Edgerton’s The Gift or even the hilarious ineptitude of glorious J.Lo train wreck The Boy Next Door. Unforgettable just plods through its expected beats, escalating Tessa’s sabotage until it turns violent. David is a naïve patsy not worthy of either of these fierce women, and at least the finale renders him unconscious while the women battle it out. Heigl remains committed all the way to the ludicrous end, and her unhinged villainy is all the movie really has going

for it.