Based on a novel and play by Robert Gore Brown, an English barrister has an affair while his wife is away.
The title of this film is inspired by Ernest Dowson's line, "I have been faithful to thee, Cynara, in my fashion." Jim Warlock (Ronald Coleman) is packing to go from Naples to South Africa when his wife Clemency (Kay Francis) asks him to explain what happened.
On their seventh wedding anniversary Jim had plans to celebrate; but Clemency is leaving for Venice with young Garla. At a restaurant Jim and John Tring (Henry Stephenson) meet Doris (Phyllis Barry) and Milly and go to the movies with them. Doris gives Jim her home and work addresses; but in the cab with John he rips them up. In Venice Clemency reads a letter from Jim. Jim speaks at a swimming contest where there are no class distinctions. He awards the prize to Doris. She sprains her ankle, and he carries her home. She lights a fire and encourages him to stay. Jim says it is not fair to her or her wife, because it couldn't last. They kiss and spend time together. Doris asks Jim for one more day, saying she would rather die than be without him. At home Jim finds that Garla is engaged to Mario. Clemency tells Jim she has never had an affair because she does not want to, though she met a Frenchman. Jim takes a call and decides not to go to a party. As Clemency goes to bed, Jim tells her she has to decide about her "copper shares." She laughs in relief. Jim meets Doris in the rain and tells her not to call him. Doris wants to go on, but Jim does not like the lies to prevent Clemency from knowing. They arrange a meeting; but later Jim writes he cannot meet and wants to make a clean break.
Jim discusses affairs with John, who notes that women hope that marriage will change the man and men that it will not change the woman; yet both are disappointed. As Jim and Clemency are planning to go out, Milly calls on Jim to ask him what he is going to do since Doris lost her job. A policeman comes in and tells Jim that Doris died from taking poison. At the hearing Milly accuses Jim of killing Doris. Jim is questioned, and the judge blames him when he refuses to say whether he was the first. Jim tells Clemency he was not the first and that he cared about Doris. Jim says good-bye to Clemency and asks her forgiveness. Clemency tells John Jim is different now; his career is ruined, and their lives are smashed up. John asks her how she would feel if she never saw Jim again. Clemency joins Jim on the boat to South Africa, and they wave to John as Jim kisses her.
This tragedy explores the difficulties an adulterous affair can pose if one wants to return to the marriage. Doris pursued the affair and was told it could not last; yet she was victimized by her own feelings.