The Stooges play three sets of identical triplets, born one year apart. All nine brothers lose track of each other after World War II, unaware that they are all living in the same city. One set is single, one is engaged, and the other is married.
Trouble brews when the engaged set of brothers decided to celebrate at a local nightclub. Before they arrive, the unmarried set show up, followed by the fiancees of their brothers. The ladies start hugging and kissing the unsuspecting brothers. Within minutes, the wives of the married brothers show up, thinking their husbands are cheating on them. Hilarity ensues when the nightclub waiter (Frank Sully) walks in and sees all nine brothers simultaneously.
In this episode, the Three Stooges all together play nine different brothers. In order to achieve this, each stooge had to stand by a marker and filming of one scene was done three times, once with each set of triplets.
A Merry Mix Up is often viewed as not only the most creative but the best Stooges short featuring Joe Besser as the third stooge. It currently holds a 6.9/10 on IMDB.