Lynn (Roxanne Scrimshaw) and Lucy (Nichola Burley) are life-long best friends, their relationship as intense as any romance. Neither has ventured far from where they grew up. Lynn, who married her first boyfriend and whose daughter is fast growing up, is delighted when the charismatic, volatile Lucy has her first baby, a boy. Lucy, however, does not react to motherhood as Lynn expects. Soon, they find their friendship tested in the most extreme circumstances.