When Mary-Kate wins praise for scoring high on her state tests, Ashley decides to throw a surprise party for her. But Mary-Kate is notoriously impossible to surprise! What if Ashley could get Mary-Kate to plan the party with her by pretending that the festivities were for their friend Lavendar's birthday? Well, if you're Mary-Kate, the party would end up being soooo Lavendar and soooo not Mary-Kate. Can Ashley change everything around in time to really suprise Mary-Kate, or will Mary-Kate figure things out as usual?