By Russ Fischer/Jan. 21, 2010 1:46 pm EST

The book takes place during the Great Depression, and follows 21-year old Jacob, who joins a second-rate circus after the death of his parents. Having once planned to become a veterinarian, Jacob is entrusted with the outfit’s mangy menagerie. He has to deal with impresario Uncle Al and animal trainer August, both of whom are crazy and eccentric. He falls in love with August’s young wife Marlena, which naturally leads to trouble.

Pattinson would obviously play Jacob and Witherspoon Marlena. The question is whether Penn would be Uncle Al or paranoid schizophrenic August. Deadline Hollywood pegs him as “the other lead in the Depression-era romantic triangle, saying he’s looking to play August. I’m OK with that; the role sounds like one that Penn could absolutely tear up, and hopefully he’d be able to have some fun with it rather than just playing dour and terrifying.

Deadline also notes that Witherspoon is looking at a role in This Means War, once meant as a Martin Lawrence vehicle but now revived with Bradley Cooper looking to star.