Hiro has finally recovered from breaking his ribs while trying to stop a mad bomber. Now that he's back in action, things don't stay quiet for long. In fact, something drastic has happened, bringing a rather unusual group from an alternate universe to theirs. But there's one problem. Hiro's universe doesn't like its new visitors and strange things begin to happen all over the city. Can Hiro and his team figure out what's going on before their universe tears itself apart?