In the suburbs of Mexico City, a very poor but loving family depends on the work of all of the members.
They however, have an enemy in El Mono, a roguish and violent boy who beats Toñito up since he believes only he should sell his newspapers in the area.
Elvira's feelings as a woman however, are stronger than those of motherhood and she chases Paco who is trying to elude the police.
In the meantime, El Mono convinces another boy to stage a fight with Pirrín so he can steal Doña Dominga's earnings.
Juancho sells his book for the injections and Doña Dominga seeks the oxygen tank to help him recover, but unfortunately while she is away Toñito dies.
Furious, El Mono decides to act alone and assaults and kills the cashier but is quickly captured by Pirrin and Juancho and is sent to jail.
As a reward, the chief executive gives Doña Dominga a brand new stand and scholarships for Pirrín and Juancho for their education.