"Sergio" (Eugenio Derbez) is a new teacher at a primary school in a run-down Mexican town where his unorthodox teaching methods cause a bit of consternation for the head teacher "Chucho" (Daniel Haddad). There's a curriculum that they are supposed to follow and this school is the very worst in the land. To inspire better results, the teachers are offered bonuses if their pupils can improve, so imagine their chagrin when "Sergio" starts upturning tables and using the school's water reservoir to illustrate the relationship between weight and density. Not only must this teacher galvanise his hithe...