It's Christmas in the Caribbean and Neville's larger-than-life mum, Melanie, is in town. She quickly assimilates herself in with the rest of the team, but she's disheartened to see how down on romance Neville is, given everything he's been through the past two years. Can she instill some festive cheer in her unlucky-in-love son? Elsewhere, a wealthy business owner called Gerry is found dead at the bottom of a ravine. It could just be an accident, but Gerry's ominous last words - 'It's behind you' - suggest something more is going on. And things take an even stranger turn when the team discover that the family's house guest has mysteriously vanished, prompting her fiance to fly out on a rescue mission.