Due to Pug's increasing amount of travel and his aversion to many of the cultural events which are enjoyed by his wife, Rhoda, she spends increasing amounts of time alone. Through Pug, she meets a widowed engineer named Palmer (Fred) Kirby, who later will be involved in the first phase of the Manhattan Project. Rhoda and Palmer begin to spend time together attending the opera and other events, but soon this leads to a romantic relationship. For his part, Pug begins a platonic but very close and borderline romantic relationship with Pamela; however, he cannot decide to leave his wife Rhoda for her.