The title character is Edmond O'Brien, a lonely travelling salesman looking for love. He finds it by marrying an eligible young woman (Joan Fontaine)--and then by marrying another eligible young woman (Ida Lupino) in another city. When one of the wives becomes suspicious of O'Brien's frequent "business trips", she takes a journey of her own and learns the truth. Directed by costar Ida Lupino, The Bigamist manages to evoke a certain amount of sympathy for Edmond O'Brien, without in any way advocating or excusing his lifestyle. It's worth noting that an Italian film made around the same time, also titled The Bigamist, is a comedy.