Howard Langley has been appointed by the courts as Merle Telford's trustee but his wife Olivia has taken full charge of her; a week shy of her 21st birthday, Merle is still childlike in many ways. When she buys airline tickets for herself and her friend Danny Pierce, Olivia cancels them and slaps Merle across the face when she resists. Danny is actually wooing the innocent Merle just to get at her diamonds; he's been working with her friend Gina Gilbert to accomplish this. Working for Olivia at the party, Paul Drake catches Merle waiting with luggage for Danny and tells her that her diamonds have been stolen from her Aunt Olivia. But when her uncle tells her that Olivia was murdered, Paul contacts Perry Mason to protect Merle's interests as the police want to search her luggage. After Perry arrives, he gives Lt. Anderson the key, and the murder weapon is found in the luggage. Many clearly wanted Olivia dead, but when the young woman is charged with murder, Perry defends her at the preliminary hearing.
—garykmcd