Franco is a minor officer who is unexpectedly confronted by Lorenzo, a half-brother with a high IQ. Lorenzo helps him investigate an apparent suicide case in which there is something more.

At a camp, Lorenzo learns about the legend of the lonely stranger. Lorenzo is excited and suggests that his companions investigate what happened.

A sniper kills three victims in different places. In the middle of the investigation, an inspector appears to assess how Lorenzo lived. Mansilla "hires" Marcelita to pretend to be Franco's girlfriend, thus covering up the mother's presence in the home.

The Montero brothers went to see a play. During the play, the main character is murdered and the culprit appears to be one of his fellow actors.

Franco is offered the position of deputy commissioner, which he accepts. At the same time, Lorenzo receives a scholarship in a program for brilliant minds that is being developed in France. Both will have to consider and deal with big changes, which could separate them.