Berni, wanting to let bygones be bygones with Briain, wishes him the best but she is stunned by his response. Has Briain burnt his bridges with Berni? Dee devises a plan to keep Katy and Mack away from each other. But will it work? Fiach, wanting to cause trouble for Mo and Colm, urges Sonia to tell Mo about the near kiss. How will Mo react?