On the distant planet of Cassini, most of the inhabitants have reasons to distrust outsiders. They have secrets to guard and true natures to conceal. When off-worlders arrive searching for a thief, it causes panic. Some fear exposure while others fear punishment and the Okami's wrath. Tasked with locating the property stolen from Eris Space Station, Lord Tanaka sends his enforcers, Tadashi and Dorian, to investigate. Against his better judgement, Tadashi decides to trust Clue's father to keep her safe and ventures to Monoceros to see to his duty.

Clue knows they mean well, but her family is wearing her nerves thin. The Okami pack and the Guardians have joined forces against her. They are determined to teach her to control her abilities because her very existence depends on it. Great-Aunt Delwyn's lessons are making Clue stronger, but they are also making her feel like a failure. When Fergus comes to her begging for help, Clue is eager for a new challenge. Well, she is until she sees what's after the pirate captain.

Gashadokuro, a giant skeleton, chases him wherever he goes and plagues him with nightmares, and Fergus needs Clue's help to find out why. Unfortunately, she knows better than to ask the Okami pack for help. They have made their opinions on certain of the double-natured clear.

With off-worlders on Cassini searching for their stolen property, will Clue be able to solve the mystery in time or will the curse of Gashadokuro expose them all?