In trying to dream up a reason that someone might want to see the new movie Unforgettable, I could come up with only one reason -- and it's more about curiosity than anything that might be termed credible persuasion. Katherine Heigl, who usually plays sweet, turns bitter to play the latest murderous ice queen to provide an audience with reasons to hiss, boo and giggle. Sporting shoulder-length blond hair that never has seen a curl and an alabaster complexion, Heigl looks like a late-model android; there's something unnervingly fake about her appearance. As directed by Denise Di Novi, from a screenplay by Christian Hodson, Unforgettable can't even manage to attain the level of superior trash. It's not for want of trying: A melodramatic story introduces us to Julia Banks (Rosario Dawson), a writer who leaves San Francisco to join her fiancé David (Geoff Stults) and his daughter Lily (Isabella Kai Rice). Traumatized by an abusive relationship in which she was beaten, Julia is ready for a new life. Enter Heigl's Tessa, David's insanely possessive former wife who intrudes herself on her husband's new relationship. Tessa ultimately carries her obsession to absurdly violent heights. A near thorough lack of plausibility and scenes that had a preview audience laughing (in the wrong places, I think) make this a preposterous entry into an already soggy spring lineup.