There are more black diamonds to be found for the Scabbard of Invincibility, so Al and Owen return to the Dragon Blood Islands to search for them. The shifty Stanley Spong informs Captain Gunner and the boys that there is treasure to be found and Blacktooth and Snotty Nell are already on their way to finding it. For a price, Stanley gives Gunner pages from an old diary belonging to Prince Alleric's butler. The diary tells of a golden casket full of sapphires which Prince Alleric deserted on an island. The map outlining its exact whereabouts, is inside an elephant statue in Alleric Castle. Determined to beat Blacktooth and Snotty Nell to the treasure, Captain Gunner and his crew sail towards Sabre Island. After a fierce battle with Blacktooth, they arrive at Alleric Castle to discover that Snotty is already there. While Snotty and her crew are sleeping, Al, Owen and Mahoot, along with Snakeboot the cat, sneak into the castle and find the map. But Snotty's daughter, Grenda, has seen them. When Gunner's crew finally finds the golden casket, Snotty attacks them and steals their treasure.
While chasing her, The Dandylion gets caught in a storm, colliding with Snotty's ship and they all end up on Shipwreck Island with no food or water. Al suggests Snotty and Gunner have a competition to see who'll end up with the golden casket, and to their surprise, Gunner wins. They are then able to go back to town and purchase a new ship, which they name The Invincible. But Al and Owen are still keen to look for the black diamonds, so they ask Gunner to take them to Alleric Castle again.
Dragon Blood 8: The Golden Casket (9780734410948)