What's a girl do when her number puts her in danger of being unmarriageable? For Ally, a 20-something with 20-something men to her credit, it's time to settle down and revisit the past. Anna Faris stars as the dizzy blonde who resolves to get serious--by tracking down all 20 of her exes to see if she missed out on Mr. Right. Chris Evans co-stars as a pal who aids in her quest.