Sandy and Kirsten convince child services officials to let them become Ryan's caretakers, and Ryan agrees to stay out of trouble. But with the upcoming cotillion, an old-fashioned formal event at which teenagers make their "debut" in society, that may be hard to do. Reluctantly, Ryan is matched with an iconoclastic East Coast girl, Anna Stern (recurring guest star SAMAIRE ARMSTRONG); to his delight, Seth is paired with the dateless Summer (recurring guest star RACHEL BILSON); Marissa plans to attend with wary Luke; and despite some individual last-minute hedging on Sandy's and Jimmy's parts, all the parents agree to accompany their children to the ceremony.Meanwhile, agents from the Security and Exchange Commission visit Sandy at work and inform him that Kirsten's check to Jimmy was not treated as an investment but was deposited into Jimmy's personal account. Outraged, Sandy threatens to tell all of Jimmy's deceived clients until Kirsten asks to talk to Jimmy first. Jimmy admits that, due to poor investments and mismanagement--along with the extravagant spending habits of his wife--he is in major financial trouble.Marissa refuses to go to the cotillion because she had an argument with Luke, and Ryan tries to avoid trouble by staying home as well. When scheming Summer accompanies Luke, rejecting poor Seth, he and Anna discover that they have a lot in common. Later, Marissa persuades Ryan to be her escort after all. At the cotillion, Greg Fisher (recurring guest star CHRISTOPHER COUSINS), one of Jimmy's wealthy clients, becomes suspicious about Jimmy's evasiveness. When Jimmy confesses that he has lost Greg's money, Greg becomes enraged and pummels Jimmy. Chaos ensues as Sandy is injured trying to protect Jimmy, and Ryan finally subdues Greg before anyone else is hurt. The event comes to an unfortunate end as the police arrive.