| Director | Philippa Lowthorpe |
|---|---|
| Genre | children's film, drama film |
| Runtime | 96 min |
| Country | United Kingdom |
| Box office | $3.9 million |
Sometime in the 1930s, with their father away, the four Walker children, John (about 15), Susan (about 12), Tatty (9 1/2) and Roger (about 7), along with their mother and baby sister, leave by train to the Lake District. On the train, they encounter a rude man who is being chased by two suspicious men.
In the Lake District, the family stay at the farm of Mr and Mrs Jackson. The farm is on Lake Windermere. While skipping stones, John breaks the window of a houseboat moored on the lake. Although the children run away, the rude man emerges from the boat and sees them. Unknown to them, the two suspicious men, who have learned that the man they are looking for is named Jim Turner, also see Turner on the houseboat. Turner visits the Jackson farm to complain to Mrs Walker about the damage caused by the stone thrown by John.
Having seen a distant island, the children wish to sail there and camp. Mr Jackson offers his sailing boat, named Swallow. John is captain of Swallow, Susan is master's mate, Tatty is able seaman and keeper of the ship’s log, and Roger is ship’s boy and lookout. They bring tents and food prepared by their mother and Mrs Jackson. Due to some bad steering, the basket with the food is lost overboard. The children make it to the island, which Tatty names “Walker Island”.
The two suspicious men observe Turner on his houseboat that night. The taller suspicious man, Zukin, suggests killing Turner, but his colleague, Lazlov, replies in Russian that they need to bring Turner in alive, as well as find papers which are hidden on the boat.
The next morning, while Susan and Roger are still sleeping, John and Tatty meet two charcoal burners on the mainland. One, Old Billy, asks John to inform the houseboat owner, whom Tatty calls Captain Flint, but Old Billy knows as Jim Turner, that two strangers have been asking questions about him.
Meanwhile, Susan and Roger discover a campsite on the island with a skull and crossbones and warning, signed “The Amazons”. They see a boat near the island flying a Jolly Roger named Amazon with two children on board. Susan realizes they must be the Amazons.
John and Tatty sail to Houseboat Bay to pass on Old Billy’s news. While inside the cabin, John sees files and photographs of planes, warships and naval guns. Turner returns and confronts John, calling him a liar and a spy. John says he only came to give Turner a message, but Turner does not want to hear anything John has to say. After John leaves, Turner packs and locks a small trunk.
While John and Tatty are sailing away, the Amazons fire a flare across Swallow’s bow. John sails back to the island to get the full crew. Swallow sails after Amazon, but Amazon, revealed to be crewed by two girls, is faster, and gets away.
The children sail to “Rio”, a local town, to get food. Roger stays with the boat if he can hold John’s pocketknife. Turner rows into Rio, observed by Roger, and Zukin and Lazlov, who are already there. Zukin follows Turner while Lazlov searches Turner’s rowboat, watched by Roger. When Roger sees that Lazlov has a gun, he drops the pocketknife into Turner’s rowboat in surprise. When Tatty returns to the general store to retrieve the ship’s log, she sees Zukin watching Turner as he writes a telegram in code, which Zukin steals.
On the island, the children are attacked with arrows by two masked and whooping children. The two attackers take off their masks to reveal they are the Amazons. The Amazons confront the Swallows. The Amazons introduce themselves as Captain Nancy and Peggy Blackett, co-owners of Amazon. The children parley at Secret Harbour, where both boats are moored. When Tatty says that the Swallows are not frightened of the Amazons or the pirate who sent them, Captain Flint, Peggy reveals he is their Uncle Jim.
The Amazons challenge the Swallows to a competition: whoever captures the other’s boat keeps it and the island. John, Susan and Roger set out at dusk to raid the Amazon’s boathouse, while Tatty stays behind on the island to light leading lights to mark the safe return course to Secret Harbour.
The Amazons, anticipating the Swallows’ night raid, turn the tables and land at Secret Harbour while Swallow is away. They plan to steal Swallow when the Walkers return. Unknown to them, Tatty has observed them. As the Amazons go inland, Tatty rows Amazon out.
Turner returns to his houseboat to find it ransacked and his trunk gone. He finds John’s pocketknife, planted by the burglars. Turner calls the Harbourmaster of Rio, reports the burglary and asks that John Walker be arrested. After signing off, Turner finds Lazlov holding a gun on him. Lazlov accuses Turner of spying on Russian shipyards and stealing plans for rockets. When Turner rejects becoming a double agent, Zukin knocks him out.
Tatty, anchored offshore on Amazon, sees two men taking something off Captain Flint’s boat and loading it onto a motorboat. John rows up to Amazon and explains that since Tatty has Amazon, the Swallows have won. They sail both boats back to the island. Captain Nancy surrenders and agrees it is now “Walker Island”. John says that it will always be “Wild Cat Island”.
The next morning, having spent the night together on the island, the children are confronted by both their mothers, the Harbourmaster and police. John is accused of theft. His pocketknife was found on the houseboat, although Turner himself is missing. While the Walker children are being taken back to the mainland, Susan sees a motorboat beached on the island. Mr Jackson locks Swallow in the boathouse.
The Walker children pool their knowledge about what has happened to Captain Flint. They agree to try to rescue Flint, with the help of the Amazons, whom they contact by flashing a message in Morse code.
The Swallows set sail at dawn. Stopping at Flint’s houseboat, John retrieves a pistol. They rendezvous on the lake with the Amazons. The Russians are holding Turner on the island.