After buying supplies, Ioz stops by a tavern for a drink and realizes that he misses being a pirate. A mysterious old man in a cloak overhears this, and tells Ioz about a ship containing such vast treasure that it is said to glow in the moonlight. Ioz thanks the man for telling the story, but dismisses it as just a tall tale. As Ioz leaves the tavern, does not notice the mysterious man vanishing after making a comment about the two maybe meeting again somewhere. Meanwhile, Bloth and his crew are searching for Ren and the others, but have lost sight of the Wraith. Morpho points them in the right direction, telling Bloth that the dark water told him where Ren will be.
Ren and the others are out sailing in the moonlight of the full moon, when the Maelstrom starts catching up to them. Ioz tells them to sail into a fog bank in order to get away from them, which seems to work. While sailing through the fog, Ioz spots a ship in the distance. Remembering the old man's tale, he decides to investigate and they sail over to the other ship. As they approach the mysterious ship, they notice that the ship appears to be abandoned. Tula claims that something is not right about the ship, as she can sense danger, but Ioz dismisses her and goes to search for treasure anyways. Ioz manages to find the treasure, only to find himself surrounded by ghost pirates. The leader, Cressa comments that her henchman picked well, and that Ioz will be a fine addition to her crew. Ioz tries to fight them, but discovers that while they can potentially harm him, his attacks just go right through the ghosts.
Ren and Tula catch up to Ioz, and try to help him fight the ghost pirates, but to no avail. Cressa orders her crew to chain Ioz, and kill the others. Ren and Tula are forced to run away, and Niddler carries them back to the Wraith. One of the ghosts tries to throw a knife at them, but the knife passes right through Ren's arm. They realize that the ghosts and their weapons are only able to harm them on their own ship. Ren tries to keep up with the ghost ship, and Ioz tricks Cressa into unlocking the chains so he can try to escape. As he tries to run away, he notices that he can suddenly harm the other ghosts, and realizes that he is slowly starting to turn into a ghost himself. The Wraith manages to catch up to the ghost ship, and Ioz almost manages to escape, only for Cressa to use her whip to pull him back onto the ghost ship.
The two ships are headed straight for a mountain, and while the ghost ship just sails through the mountain, the Wraith runs aground. Ren realizes that the ghost ship may be inside the island, and takes Tula with him to investigate. Entering a tunnel, they manage to find the ghost ship and sneak on board. Ren and Tula find Ioz, and discover that he is turning into a ghost. Ioz tells them that if he doesn't get off the ship by moonrise, he will become a ghost forever. Ren tries to free him, but his sword can't cut through the ghostly chains, and he is unable to use one of the ghost pirates' weapons as his hands just pass through them. The ghost pirates return, and Ren and Tula are forced to escape again. Ren swears that he will come back for Ioz, and the ghost pirates attack the boat.
Ren and Tula manage to escape the ghost pirates, but are now having even more problems now as the Maelstrom has caught up to them. Ren and Tula are captured by Bloth's crew, while Niddler tries to escape. Konk tries to capture Niddler, but is distracted by the ghost ship. Bloth plans on throwing Ren and Tula to the Contrictus, but Morpho suggests that they would be more useful as dark diciples. Bloth gives him permission, and has Ren and Tula locked up while Morpho goes to prepare the potion. Konk is set to the guard the prison cell, but is unable to focus because the presence of the ghost ship makes him nervous. This gives Tula an idea on how to escape, and she and Ren gather up the dust inside the cell. Tula manipulates the dust and makes Konk believe he is being attacked by a ghost pirate, causing him to throw his sword and the key at it before running away in fear.
As they escape from the cell, Ren says they have to save Ioz before it's too late. Tula realizes that the only way to defeat a ghost is to become one, and suggests to use her powers to lower Ren's body temparature until his spirit leaves his body. Hearing Bloth approaching, the two of them hide and Tula warns Ren that if his spirit does not make it back to his body in time, he will die. Ren tells her that he is not afraid, and Tula uses her powers, separating Ren's spirit from his body. Ren's spirit goes to fight the ghosts, as Bloth and Konk show up. Konk believes the ghost pirate killed Ren, but Bloth doubts that the ghost pirates were responsible for Ren's apparent death. Bloth takes Tula away to be turned into a dark diciple so that he will be rid of both his enemies, leaving Ren's body behind.
Niddler is unsure of what to do, with both the ghost ship and Bloth to worry about. Ren's spirit flies past him, and tells Niddler to stay close by in case he needs help. In only a minute or so, Ioz will turn completely into a ghost, and Ioz curses himself for his greediness. Ren shows up to challenge Cressa, and as a spirit is now able to fight back. Ren after fighting off some of the ghost pirates, Cressa goes to fight Ren herself, but Ren eventually manages to knock her off the ghost ship. Before Cressa manages to climb back onto the ship, Ren goes to free Ioz, but Ioz thinks it might already be too late. Ren looks over at Cressa's hourglass, and realizes that there's still a little time left. As the two of them are about to get off the ship, Ren's spirit begins to fade, and he realizes that he is running out of time. Ioz gets off the ghost ship, while Ren has to hurry back to his body. Ioz returns to normal, and Niddler pulls him out of the water just before some dark water tries to devour him.
Ren manages to get back to his body in time, and notices that Tula is not there as the Contrictus suddenly shows up. Morpho is about to turn Tula into a dark diciple, but Ren rides the Constrictus, and manages to save her. Bloth tries to attack, but Niddler drops Ioz on him as a distraction. Ren, Tula, Ioz and Niddler manage to escape, and Konk notices the ghost ship sailing by and the treasure it contains. Bloth throws Konk onto the ghost ship, and one of Cressa's crewmates asks her if she would like to have him on her crew. Cressa simply states that she lost the one she wanted, and the ghost pirates throw Konk overboard.
Back on the Wraith, Ioz asks Ren not to tell Tula about him cursing himself for his greediness back on the ghost ship, and Ren promises not to tell.