In an amusing tale of friendship and adventure, Addison meets Daisy Dixon when her family drives to Delaware. Daisy is a dainty girl with dangling curls, who wears dandelion-colored shoes, and has a disability. They did not know anything about disabilities, so Addison and Albert are unsure of how to act around Daisy but soon learn that she is full of surprises. When they discover a hidden clue, they dive into the thrilling mystery of the Delaware Swamp Monster, and their detective skills come into play as they devise a plan to create a new swamp monster! When the swamp monster crashes their party, monster mayhem develops, making Daisy's party a memorable Delaware event!