Mad Hot Ballroom was one of the most exciting, surprising and entertaining documentaries of 2005, a summer that also boasted March of the Penguins. So you'd figure director Marilyn Agrelo would have been flooded with offers and given her pick of Hollywood to work with for her first fiction feature. Not, you might imagine, Jessica Alba.

But that's exactly who is set to star in An Invisible Sign of My Own, reports Variety, which will be Agrelo's first film since Ballroom. Much like Alba's recent role as a world-class violinist in The Eye, the part here seems a little atypical for the starlet: She'll play a young woman who is obsessed with math, and then becomes a second-grade math teacher.

The screenplay is written by the people responsible for The Wedding Planner, Pam Falk and Mike Ellis, which just adds another level of mediocrity. I'm not sure what took Agrelo so long to make a follow-up to her smash hit documentary, but I'm betting she wasn't simply waiting for a project as promising as this one to come along. At least Agrelo stands a decent chance of making Alba do something she's yet accomplished onscreen-- seem like a real person.