Iain Glen's gruff, hard-drinking Garda gumshoe returns for the final episode of the miniseries. Riddled with guilt after a personal tragedy, Jack leaves Galway for Dublin. There he meets Rosie, a young girl who witnessed her mother's murder, but has suppressed the memory. While also dealing with a travellers' feud, Jack must help Rosie to recall the events of her mother's death before the killer strikes again.