This summer, Arthur is going on a family vacation. Only he'd rather be with his friend Buster. The hotel pool is no bigger than a bathtub, it's pouring rain and his little sister D.W. seems peskier than ever. Arthur is tired of having nothing to write post cards about, so he decides to find new things for his family to do. Arthur's unexpected outings are a blast - even in the rain! Maybe family vacation isn't so bad after all!