Don't Ever Leave Me (1949)

In a pleasant variation on "The Ransom of Red Chief," elderly crook Harry Denton, when challenged to prove he is "not past it," decides to kidnap Sheila Farlane, the 16 year old daughter of a famous actor. When Harry loses his nerve, Sheila won't let him give up. Because she is bored and ignored by her egotistical father, she becomes the mastermind of the plot. Harry's grandson Jack, who feels responsible for the old man and the girl, is shocked, and tries to return Sheila, but is thwarted by her determined fantasizing.