From the publisher:
Nancy and Peggy Blackett receive a letter from their Uncle Jim who's on his way home after failing to find treasure in South America. When they hear a tale about a lost gold mine in the Lake District hills, Nancy and Peggy decide to find the mine as a surprise for their uncle. The children comb the nearby hills, while being shadowed by a mysterious figure they dub "squashy hat." Undeterred by drought, sudden brushfires, and the continuing presence of Squashy Hat, the young prospectors persevere in their quest--with surprising results (aided by Dick's knowledge of chemistry).
