Hupo is off on an airship adventure, but this time he's sharing the decks with Zimmy, a peculiar person who looks, sounds, and smells, just like Hupo! They make their way to the Doom Lagoons, a place where you can trap your worst fears below the waters so you never have to be scared again. But things don't go to plan, and after hundreds of years of fear is released into Yip, it's up to Hupo and the suspicious Zimmy to save everyone from the horrors of the Doom Lagoon!