After living all his chilhood in the street, a young boy notices rapidly that crime doesn't pay and that´s why he decides to become a policeman. One day, one of his best friends go in prison for a murder he didn't commit. Immediately the policeman tries his best to release him and prove his innocence.

The East Side boxing champion Muggs answers a challenge to a fight against the West Side champ but just before the match he is kidnapped. His friend Danny Lyons takes his place and wins the fight, only to have Mugs believe that Danny was responsible for his kidnapping.

The gang is friend with a millionaire because they saved him from an agression. However, the gang is suspecting that the man's son was actually one of the agressors.

The gang is sent to the Wilton Reform School after they are unjustly convicted of stealing a truck. Bill Collins, brother of co-leader Danny, becomes involved in a killing and, while also innocent, is convicted and sentenced to death. Through a series of events, Muggs, Glimpy, Danny and the rest of the gang, learn that Knobby, a henchm...

Muggs is tricked into entering a Civilian Conservation Corps camp by Danny in order to get in shape. Muggs resists and battles with the camp captain and with other campers. He also becomes involved in trying to help one of his friends get out of trouble.