Mary-Kate and Ashley are psyched to see their friend Patty perform her Irish dance in the talent contest at the mall. But before Patty goes on stage, her emerald shamrock pin is stolen! The twins are sure they'll find Patty's pin in no time. After all, the thief left behind a chocolate fingerprint. But the case gets tougher when more jewelry turns up missing. Now the talent show might be cancelled — unless Mary-Kate and Ashley can find the chocolate-loving thief lickety split!