Borderline is about a woman, victim of the cruelty and violence, and a man, Gabriel, a fifty-year-old director in search of celebrity.

Antonio is a man born with unusually large incisors; his freakishly huge teeth made him an outcast as a child and as man he has become obsessive and controlling in his relationships with women. Convinced that his girlfriend cheated on him (with her dentist, ça va sans dire), Antonio insults her in a fit of anger and in the fight she breaks off one of his teeth. Antonio now must travel across the country, going from dentist to dentist in search of someone who can make a crown that will suit his extra-large smile.