The Adventures of Mary-Kate & Ashley is a series of musical mystery videos starring twin actresses Mary-Kate & Ashley Olsen. The series was also written as children's books, usually showing the twins on the cover. Each episode begins with the girls singing the theme song. Following the theme song, the girls receive a phone call, informing them of some urgent mystery that needs to be solved. The girls jump at the opportunity and say their motto, "We'll solve any crime by dinnertime!" Each episode features the girls singing multiple songs about the mystery they are working on. They never fail to solve the mystery with their sidekick, Clue (a Basset Hound), and, indeed, the solution is usually something either very obvious or very trivial, to give the video a humorous ending.