Ever since Al Capone built Happyland Amusement Park in the 1930s, treasure hunters have believed Capone’s lost fortune awaits somewhere at the end of a hidden ride no one has ever found… until tonight. When Henry (Lucas Jade Zumann) finds a set of blueprints leading to the loot, he recruits his best friend and big sister on the quest. The kids quickly find themselves on an incredible adventure when they sneak into the abandoned park and witness it’s attractions magically come to life. To make it out alive, Henry and his pals must team up with a friendly sea witch (THIRD ROCK FROM THE SUN’s Kristen Johnston) to do battle against an evil mermaid, deadly pirates, a fire-breathing dragon and an armada of blood-thirsty monsters. And all on a school night!