Winter Holiday (Swallows and Amazons)

Arthur Ransome's Swallows and Amazons series has stood the test of time. Ransome is not only a great storyteller, writing from first-hand experience, but each story celebrates eternally valuable qualities of practical knowledge, independence, and initiative. The twelve books are for children or grownups―anyone captivated by a world of sailing, adventure, and imagination.
The fourth book in the series, Winter Holiday, takes intrepid explorers John, Susan, Titty, and Roger Walker, and fearsome Amazon pirates Nancy and Peggy Blackett to the North Pole. Joined by budding novelist Dorethes Callum and her scientist brother Dick, the children plan an Arctic expedition. But unforeseen events separate the travelers and disaster nearly strikes in the exciting climax of their race to the Pole.