THERE'S TROUBLE IN WONDERLAND -- THE MAD HATTER'S HAT IS MISSING!Nancy's class is performing Alice in Wonderland and everyone is busy practicing for the big day. Rehearsals are running smoothly until the Mad Hatter, pesky Orson Wong, discovers that his "magic" hat has vanished. How will the Mad Hatter remember his lines without it?Sounds like a case for Nancy Drew. But Nancy's not so sure she wants to solve this one -- Orson is such a pest! Even worse, Orson wants to help Nancy solve his own case, and Nancy's friends won't even investigate the case if he's around. Will a new partner mean saying good-bye to old friends? And can Nancy and Orson uncover the Hatter's hat before curtain time?