A group of teens trick a bully into joining them for a day on the river, intending to humiliate him. But their sympathies, and ours, get confused when the bully turns out to be by turns sweetly vulnerable, pathetically desperate in his attempts to make friends, and suddenly savage in his fury when things go wrong. In this subtle examination of group dynamics by writer-director Jacob Estes, each character struggles with moral questions. Everyone in the cast conveys that messy mix of teen self-consciousness and bravado, but Josh Peck is particularly nuanced as the bully. R, 89 min.