Complex sentence: He enlists his mistress, Peaches (played by Hall), and her brother to stage a mock kidnapping, and to make and receive huge ransom demand, which would keep the money safe from his wife.
Split into simpler sentences: He enlists his mistress, Peaches (played by Hall), and her brother to stage a mock kidnapping. They are to make and receive huge ransom demand, which would keep the money safe from his wife.