Josh reluctantly goes to spend part of the summer in a remote area of Wales, where his dad is working. He expects boredom, but by the sea and in the shadow of the ancient village church, he ends up discovering a mystery that he's determined to solve before time runs out. A frightening farmer, a long-lost tunnel, glimpses of mysterious barrels floating out to sea and reports of a ghost ship, are all part of the puzzle and Josh has to work out if and how they are connected before he can solve the mystery. Will his daring plan succeed?