Scottish director Michael Caton-Jones’ new movie harks back to his sister’s girlhood in West Lothian, as he tells Isabelle Grey

Our Ladies is a tender and poignant road movie about a ­raucous group of Catholic girls who certainly do not see themselves as either tender or poignant. Based on Alan Warner’s 1998 novel, The Sopranos, it follows a tight-knit gang of five 17-year-olds from the Highlands convent school Our Lady of Perpetual Succour who occupy the “party end” of the coach that is taking them to a choir competition in Edinburgh.

The teacher accompanying them, Sister Condron (Kate Dickie), warns them that the beautiful city is also a place of sinful wickedness. “You will,” she tells them, “carry yourselves with grace today.” The story, set in 1996, explores the nature and consequences of their individual interpretations of that grace.