Sheldon treats Andie, a woman who may suffer from multiple personality disorder. Her sister, Laura, says their parents died when they were young but it’s been years since any of Andie’s other personalities have shown up. Sheldon learns that’s not the case any longer when a personality named Gina advises that he back the hell off. One of Andie’s other personalities, Maggie, is upset because Laura’s fiancé, Jack, his taking her sister away with him to start a new job in Arizona.
Sheldon eventually discovers that Andie is faking the disorder. The reason is a shocker. It’s because she’s in love with Jack and she doesn’t want her sister to take him away from her. Laura is furious, but Andie is still her sister. That means she still wants her in her life. Jack does, too. With Sheldon’s help, they’ll figure out away to make it all work.