Mac an Athar is the story of Seán, a 12 year-old boy raised in the Irish language on Dublin's Northside, who encounters ridicule for his "unorthodox" upbringing.

Ireland 1981. Nine-year-old Cáit counters the adversities of a life in poverty on the countryside with a quiet retreat into her own world: She is a sensitive observer of the beauty of the small things around her. When she is sent from her overwhelmed, often emotionally cold extended family to an older, childless couple during the holidays, she experiences deep affection, perhaps for the first time ever.