A traveling Samurai exhibit, rumored to be haunted, comes to the museum. When, Henry discovers that some of the exhibit items are being stolen, he is not believed by his uncle. Henry, Maggie and Jasper therefore try to take matters into their own hands, shadowing a martial artist, who they suspect is the thief.

Henry tries to clear his uncle's name by solving the murder of the former partner of Jasper's father and finding a Viking artifact that he was looking for.