Wilma Tenderfoot's dreams have come true. She is now an apprentice detective to the famous Theodore Goodman, and she is one step closer to finding out what happened to her parents. Now a new case has come up for Theodore - actors at the Valiant Vaudeville Theatre are being poisoned one by one and the criminal is at large. Wilma may be small, but she's determined to put her apprenticeship skills to the test. Then, right in the middle of the investigation, Theodore disappears! Wilma is on her own (with her loyal beagle, Pickle, of course) and decides her best bet is to go undercover to solve the case. But will she unmask the poisoner before <i>she</i> is the next target?