Diana Hesse Jr., the daughter of Dr. Alex Hesse (played by Arnold Schwarzenegger) and Dr. Diana Reddin (played by Emma Thompson), is all grown up and ready to marry her childhood friend, Jack Arbogast, the son of Dr. Larry Arbogast (played by Danny DeVito) from the first movie. However, as the wedding preparations begin, Diana stumbles upon some mysterious documents that raise questions about her own birth and existence. Thus begins a comedic journey to uncover the truth and ensure that Diana can legally exist and get married.
