Fun-loving otters, frisky Airedales, and the MacMurroughs, a spirited adventurous family with eleven-year-old twins, Jonathan and Juliette, come together in Philadelphia. Competition and sibling rivalry take turns with William Penn's theme of brotherly-love as the Airedales and Otters spend time with each other, share food, slide down hills, and challenge each other in swimming and tug of war contests.