The Great Scramble for Treasure! Collapse! Spa Island!

After Lina reveals that she has searched all over the ship, Luffy decides to destroy the ship in order to find Sayo. The Straw Hats manage to fight off Doran's men, but Doran unveils a large cannon and aims it at Sayo. Sayo tells Lina that their father truly cared for them and believed that his research would bear fruit, and left in order to protect them from his pursuers. The Straw Hats manage to rescue Sayo and destroy Spa Island, and notice that the X on Lina's father's map pointed to an X-shaped underwater volcano opening beneath the island. Several days later, Sayo and Lina complete the gem and send it to the Straw Hats, but as candy rain falls on the Sunny, Luffy accidentally loses it.