A confident young cop is shown the ropes by a veteran partner in the dangerous gang-controlled barrios of Los Angeles, where the gang culture is enforced by the colors the members wear.

A young inductee into the military is given the task of looking after some chimpanzees used in the mysterious 'Project X'. Getting to know the chimps fairly well, he begins to suspect there is more to the secret project than he is being told.

21 Jump Street revolves around a group of young cops who would use their youthful appearance to go undercover and solve crimes involving teenagers and young adults.