Letters to Enid volume 10
On my bookcase part 2
The Isle of Gloom is an island off the coast near Craggy Tops – the home of Aunt Polly and Uncle Jocelyn. It is a mysterious and deserted place, almost constantly shrouded in mist so that it can barely be seen from the mainland. Of course it is teaming with bird-life so the children end up visiting it, and find tumbledown huts and old mine shafts. The most interesting things about the Isle of Gloom are found underground, however. A network of mine tunnels that contain some dodgy characters, and lead to an undersea tunnel.
The Treasure Hunters is a shortish but satisfying story about three children who go to stay with Granny and Grandpa during the hols. They are close to losing Greyling’s Manor, the family’s ancestral home, and wish they could find the mythical Greyling’s Treasure to pay off their debts. The house has at least one secret passage, and huge grounds to explore. The children discover an old summer-house and inside, a hidden box containing a map. All that’s left for them to do is decipher the map, find the treasure and save the day. But Mr Potts who wants to buy the manor keeps popping up, jovial on the outside but sinister underneath.