Two things would have been apparent to 1952 audience that the current viewers may not be aware, and they both affect understanding this episode.
Alan(Frank Overton) is at least 30, and the original viewers would have recognized him as a veteran of WWII, living the veterans dream of living in his hometown among friends and family, not regimented in a regular job, but doing what he wanted when he wanted, and looking for a nice girl to marry and start a family. He has had all the excitement he wants in his life.
But the girl (Peggy Ann Garner) is much younger, only a child during the war, married for the exciting life and money of her gangster husband. Now being part of that dangerous lifestyle threatens her as much as the war threatened Alan. Her character is really irritating, because she has not grown up yet, but she starts to by the end of the episode.
Ironically, those 2 main actors situations were completely opposite the roles they played. Peggy Ann Garner was known internationally for her childhood movie roles in Jane Eyre( Elizabeth Taylor had an uncredited bit part), and A Tree Grows in Brooklyn, for which she won an AcademyAward.
Frank Overton may have been known locally(NYC) from his performances on Broadway and summer stock, but he had had only 3 bit parts in movies, and this was only his fifth TV role, and the biggest. From this point on, his career kept growing, and hers stagnated.