When teenage Bennie (Alden Ehrenreich) arrives in Argentina to look for his long-estranged brother, Tetro (Vincent Gallo), he finds not the idolized sibling from his youth, but a tormented and self-destructive soul who has abandoned his brilliant career as a writer. After Tetro rejects him, Bennie risks his brother's wrath by secretly completing one of his plays and submitting it for consideration for a prestigious literary prize.