Swallows and Amazons follows four children who dream of escaping from the tedium of a summer holiday. When finally given permission to camp on their own on a remote island in the middle of a vast lake, they are overjoyed. But when they arrive, they discover they may not be alone and a desperate yet whimsical battle for ownership of the island ensues, where both skill and luck play a hand. Simultaneously, the dangers of an adult world, on the brink of war, encroach on their paradise and intertwine with their lives, in the form of a mysterious pair of Russian spies hot on the tail of the enigmatic Jim Turner. The children must ban together from both groups, learn skills of survival, responsibility, and the all-important value of friendship to save a family member.