Margaret, a divorced woman living alone in Dublin, learns that her teenage son has been found dead. Enduring her unsettling grief privately, she escapes daily to the local swimming pool. One day at the pool she runs into Joe, a homeless youth she found injured late one night in the deserted laneway behind her work. Margaret offers Joe a room in her house and an unorthodox relationship starts to develop between them. Margaret’s ex-husband Matt begins to turn up randomly in Margaret’s life. As Margaret and Joe’s mutual reliance grows their tentative trust is threatened by the escalation of Matt’s grieving rage and Joe’s involvement with a gang of violent youths.