Or so Nancy thinks. Then the lake ices over completely and the Swallows and Amazons, along with Dick and Dorothea - "the D"s" - plan a race to find the North Pole. How will they reach it if they can"t sail? By sledges of course! But when a blizzard blows up and there is a mix up about signals, the D"s disappear into the Arctic night. Disaster looms. Can the Swallows and Amazons save their friends?