This movie takes place after the events of the Season 4 finale. Focused on the trio, they accidentally get lefted behind in El Paso, but fortunately, they get help from a boy named Eric. Meanwhile, having discovered about their predicament, five of the students of Aberdale Elementary head out to save them.
The film features Trey Parker, Alan Tudyk, Kristin Chenoweth and Matt Damon as the new characters.
Further information: https://ideas.wikia.com/wiki/Clarence%27s_Big_Break