Death Valley is a place where drunk college kids can run wild on weekends without fear of the police shutting them down. This small desert town is home to a local Biker gang known as the Legion of Outlaws, an MC who traffic drugs and prostitution through this quiet community. Death Valley is also a place where getting attacked by a werewolf is nothing out of the ordinary especially during a full moon.

Pop sensations Alvin, Simon and Theodore end up in the care of Dave Seville's twenty-something nephew Toby. The boys must put aside music super stardom to return to school, and are tasked with saving the school's music program by winning the $25,000 prize in a battle of the bands. But the Chipmunks unexpectedly meet their match in three singing chipmunks known as The Chipettes - Brittany, Eleanor and Jeanette. Romantic and musical sparks are ignited when the Chipmunks and Chipettes square off.