Roald & Beatrix, the tail of the curious mouse, a heart-warming Christmas film inspired by the true encounter between a six-year-old Roald Dahl and his idol Beatrix Potter. A magical story of what really can happen when you are brave enough to follow your dreams. ing Dawn French who plays Beatrix, the cast includes Jessica Hynes, Rob Brydon, Alison Stean, Nina Sosanya, Bill Bailey and Nick Mohammed.