The fourth installation in the Step Up dance series focuses on fusing flash mobs with dance numbers that stick it to the man, which (sorta) explains the `Revolution` in the title. In this one, we have a group of street dancers called The Mob; its leader Sean (Ryan Guzman) quickly falls for Emily (Kathryn McCormick), a skilled ballerina who also happens to be the daughter of a real-state entrepreneur (Peter Gallaghar). Apparently, Emily`s daddy has plans to bulldoze Sean`s neighborhood, and The Mob won`t stand for that, nosireeâ€