When siblings Julian, Dick and Anne learn that they cannot go for their usual summer holiday to Polseath, they are invited to spend the summer with their Aunt Fanny and Uncle Quentin at their home Kirrin Cottage, in the coastal village of Kirrin. They also meet their cousin Georgina, a surly, difficult girl, who tries hard to live like a boy and only answers to the name George. Despite an uncomfortable start, the cousins become firm friends and George even introduces them to her beloved dog Timothy (Timmy), who secretly lives with a fisher boy in the village after George realises that her parents will not allow her to keep Timmy.
George agrees to take her cousins to the nearby Kirrin Island, which belongs to her mother's family. On their way to the island, she shows them a shipwreck, which George explains was her great-great-great grandfather's ship. He had been transporting gold when the ship was wrecked in a storm, but despite divers investigating the wreck, the gold was never found. After visiting the wreck, the five arrive on Kirrin Island and are exploring the ruined castle when a huge storm blows up, making it too dangerous for them to return to the mainland. Deciding to take shelter on the island, they witness the sea throwing up the old shipwreck, grounding it on the rocks surrounding the island. Excited by these developments, they decide to come back at dawn the next day to investigate the wreck before it is discovered.
The next day, the five visit the wreck and discover the captain's cabin, where they find some objects belonging to George's great-great-grandfather, including an old box which they take back to Kirrin Cottage, hoping to find out what's inside. The box proves difficult to open however, so they decide to throw it from the highest window of the house. The box is broken open, but the noise disturbs Uncle Quentin who confiscates it. Not willing to give up their quest, Julian sneaks into Uncle Quentin's study and takes the box, which contains an old map of Kirrin Castle. The children realise that it is a treasure map showing the location of the Kirrin's lost gold, so after taking a tracing of the map and returning the box, they make plans to find the gold themselves.
To the children's shock, they are told that the box containing the map has been sold to an antique collector. The same man also makes an offer to buy Kirrin Island. The children realise he has unearthed the secret map and wants the gold for himself, and so begins a race for the five to get to the gold first. Thinking the children want to spend time there before it is sold, Uncle Quentin and Aunt Fanny agree to let the children go camping on Kirrin Island, and they set off hoping to find the lost gold.
Arriving on the island, the five start searching the castle ruins to locate the old dungeons where the gold is hidden. Chasing a rabbit, Timmy the dog accidentally falls down the old well, which the children use to help them find the dungeon entrance. Exploring underground, they find the gold still there in a locked vault. Trouble soon arrives, as bad men come to the island hoping to steal the gold. They capture George and Julian, locking them in the dungeons. Unable to find Anne and Dick, they leave the island, taking the oars from the children's boat so they can't escape. Anne and Dick use the well shaft to rescue Julian and George from the dungeon and the children hatch a plan to trap the men when they come back to the island with a boat to steal the gold.
The plan is a success and they manage to leave the men stranded on Kirrin Island. They return to the mainland to tell Uncle Quentin, Aunt Fanny and the Police what has happened. The gold is recovered and it is decided that it legally belongs to George's family, making them rich and enabling them to afford everything they have ever wanted. George's only wish is to be allowed to keep Timmy the dog and her parents agree. George also agrees to go to boarding school with Anne, because she and her cousins have become close friends.
можешь сократить не полностью писать