With their two grown children gone, Anja and Michael Wagner move into their own apartment in the city center. Both are looking forward to their newfound freedom. But when Niklas, their youngest child, is kicked out of his roommate's apartment, he decides to move in with them and his girlfriend.

This is the third and final part of the now famously successful trilogy, where Mr. Müller and his problem kids Chantal, Danger and Co. once again take up arms against their sworn enemy, the German education system.