S1, E1: David Jason and Maggie Smith lead an all-star cast in Alma Cullen's First World War drama about the mysterious disappearance of the Sandringham Company at Gallipoli in 1915. The loss of the King George V battalion brought the true horror of the First World War to the heart of the establishment, and to the British Royal Family itself. This is the story of the amateur soldiers, the grooms, servants and gardeners of the King's Norfolk Estate, and what happened to them on the fateful day of their very first battle.