It's considered one of the finest comedies of Mexican cinema, and is adapted from the screenplay for the MGM movie Merrily We Live (1938).

In a mansion outside a nameless city (apparently Mexico City), lives the wealthy Valverde family: the patriarch Miguel (Oscar Pulido) a businessman; Emilia (Blanca de Castejón), his wife, a fun and good-hearted but slightly deranged woman; and their two daughters: the oldest, Susi, short for Susana, (Miroslava) and Lala, a nickname for Laura (Anabelle Gutiérrez).

The car then starts going downhill in reverse until it falls off a cliff and gets destroyed, so he has to walk to find help and ends up in Valverde's home, asking to make a phone call; because of his dirty and ragged clothes, Emilia takes him for a tramp and invites him to stay with them.

In the following days, he proves to be more than a regular homeless man: helping Miguel when he arrives home drunk, enchanting the heart of Susi, and especially during a business dinner where he secures Miguel's financial investment support from a bank manager but also making Susi jealous after the manager's daughter, Patricia, insists on dating him the next day.

The following day when they look for Alberto, they don't find him in the bedroom, then Miguel reads a note in the newspaper where they are informed he died in a car accident, causing a chaotic chain of faints and madness around the house.