Every superhero has a weakness — hell, any hero of any kind has one. That's what makes an exciting story. But some characters have lamer Achilles Heels than others. In fact, there's a whole collection of movie characters who are completely, tragically, and hilariously undone by water. Take Peeta Mellark, for example. Peeta already suffers from a severe lack of battle skills, and turns out to be seriously lacking in the swimming department, which becomes a major issue in Catching Fire. The second Hunger Games book's arena is made up of mostly water, thus forcing the tributes to swim to shore to avoid the fishy beasts that are out to eat them. This is not exactly a competition where Peeta shines.