Somewhere in Mexico City, Octavio (GAEL GARCÍA BERNAL) is a young man who lives with his brother, Ramiro (MARCO PERÉZ), that man's wife, Susana (VANESSA BAUCHE), and their dog, Cofi. Ramiro treats Susana horribly, a point that hasn't escaped the attention of Octavio who's found himself now in love with her. While they begin an affair and he wants her to run off with him, she's hesitant because he has no money.
When Cofi ends up killing a dog-fighting champion canine owned by local hood, Jarocho (GUSTAVO SANCHEZ PARRA), Octavio decides to enter the dog into such contests to raise money for Susana, and he's soon making more than he ever could have imagined. Yet, a series of events ends all of that and results in a bad car accident that leads to the film's second story. In it, Valeria (GOYA TOLEDO) is a leggy model whose body adorns large billboards across the city. She's having an affair with Daniel (ÁLVARO GUERRERO), an executive who's left his wife and kids to be with her.
When she's seriously injured in that car accident, her and Daniel's lives are forever turned upside down, a point only worsened when her beloved dog jumps through a new hole in their apartment floor and disappears. As the two try to find and remove the pooch, they must also contend with the likelihood that her modeling career is over.
In the film's third story, El Chivo (EMILIO ECHEVARRÍA) appears to be a street derelict who's actually a former anarchist who now makes a living as a hired assassin. His latest hire - arranged by a local corrupt cop, Leonardo (JOSÉ SEFAMI) - is Gustavo (RODRIGO MURRAY) who wants his partner and half-brother killed. While preparing for that hit and tending to his many dogs as well as one that he rescued from the car accident, Chivo also follows and tries to make contact with his now adult daughter, Maru (LOURDES ECHEVARRÍA), that he abandoned long ago.