During summer vacation, Beanie is spending two weeks on his Grandpa and Grandma’s farm, and brings Admiral Bubbles along so he can keep an eye on him. There he meets May-Rose, a farm girl from the neighbouring farm. With Beanie’s grandparents distracted by a drought, and Beanie drafted into helping around the farm, suddenly his goldfish has a little “free time” on his fins. When he and Beanie stumble upon his scale model of an underground military base that Beanie’ great-grandfather built, Beanie assumes it’s just a toy—but Admiral Bubbles knows better. He quickly sets off to find the hidden base and discovers within a secret experimental submarine-like tank that can tunnel underground. Admiral Bubbles takes control of the vehicle and wreaks havoc, even chasing down May-Rose until Beanie can sneak aboard to wrest the controls from his formidable fishy foe. Admiral Bubbles admits defeat, but the effects of all the underground tunneling unleash a hidden spring which floods the tunnels and irrigates the farmland once more, much to the embarrassment of Admiral Bubbles.