Five Go to Smuggler's Top

Blurb

Five Go to Smuggler's Top is the fourth book in the Famous Five series by the British author, Enid Blyton.
Plot Summary
The Five are sent away to Smugglers Top after a tree blows onto Kirrin Cottage. Once there they make friends with Sooty and his sister Marybelle, however their father would not have dogs in the house so Timmy had to spend his time there in secret passages. The boys spotted a light flashing in the houses tower. They think it is Block in the tower but then see him in bed at the same time. Uncle Quentin comes to stay with them but mysteriously disappears along with Sooty. The Five find a secret passage leading underground to where Sooty and uncle Quentin are held captive with Timmy. They fight off the kidnappers and go back to the house where they realise Uncle Quentin and Sootys father are planning to drain the marshes stopping the smugglers and Block had been put into their household to stop the plans. They call the police to capture the smugglers using Timmy to find them in the underground tunnels.