As the title suggests, it's a modern fairy tale about a high school physics geek, Casey (Michelle Trachtenberg), who discovers her latent talent for figure skating. But in Tim Fywell's family film, there's a darker thread too about brittle single mothers who lean on their daughters to pursue opportunities they themselves have lost. For ice-skating coach Kim Cattrall that means pushing the boundaries of fair play (we know now that this pretty world harbors real villains). And while it saddens me to see a great quirky actress sidelined to a supporting-mom role (that's a tolling bell for Hollywood actresses), Joan Cusack easily rises above the predictability of the story. Her portrayal of Casey's funky, granola-and-books mom carries real poignancy, and I felt her heartbreak when her bright, Harvard-bound daughter morphs into a sequined, whirling ice princess. Starts Fri., March 18.