The title character is Edmond O'Brien, a lonely travelling salesman who ends up married to two women, Eve (Joan Fontaine)--and Phyllis (Ida Lupino). Eventually, of course, the truth comes out. 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.