Fabian and Casimiro are two respectable married men, who have their little adventures every now and then, like any good husband. The problem begins to Fabian when his wife Adela, accompanied by her friend Martirio, discover him with another woman. After this, and as revenge Adela decides to return the ball to Fabian, with his best friend. Aware of the plan, Fabian looks for someone to solve thesituation and finds Casimiro, which is suitable, precisely because he lacks "it".

By a misunderstanding two employees of a pharmacy, Alberto and Juan, delivers rat poison to a client.