Businessman Mark Adler is found dead in a cryotherapy facility associated with his formerly ailing rugby team, the Causton Lions, coached by Bill Viner, a former player his age, whose career was wrecked by a knee injury. Barnaby and Winter look into club rivalry, notably problematic star player Danny Wickham, and Belinda Braun and her grandson Dominic, who works as innovative festive pastry chef in the former family bakery now owned by Mark's widow Samantha.