An advertising executive falls in love with his best friend's fiancé; they marry but quarrel until their friend causes them to forget.
In New York Sky Ames (Lew Ayres) shows secretary Miss Wilson (Sara Haden) he is engaged, and his friend Jeff Holland (Robert Taylor) greets him but is smitten by Sky's fiancé Linda Bronson (Greer Garson). Jeff sends Sky off to work and misses his meeting with McIntyre (George Barbier). Sky meets Linda's parents Louise Bronson (Billie Burke) and George Bronson (Reginald Owen). Linda arrives with Jeff. Louise shows Jeff a saddle, and Linda lends Jeff George's riding outfit. On a fox hunt Jeff falls in the water and pulls in Linda. In a barn they kiss as Sky and her parents arrive. On a golf course Sky tells Linda to keep seeing Jeff. In a tour bus Jeff and Linda try to forget Sky and plan to elope. Jeff forgets their appointment at 2:30 but runs after her. They kiss in a taxi, and Jeff stops to give McIntyre sketches. McIntyre and Sky show Jeff the laboratory and a drug that makes a person forget everything. Linda heads home, and Jeff follows her. A motorcycle cop (Paul Hurst) stops both cabs, and Jeff says they are eloping. Linda directs them to the home of Judge Milliken (Henry Travers), who marries them.
Linda called Sky to their new home, and Sky brings a corsage. Linda suggests they adopt Sky. Louise instructs the surprise party to hide. Jeff comes home late again, and Linda complains, saying Sky is more attentive. While people hide, Jeff criticizes Linda's relatives and friends. Then Jeff and Linda are surprised. Jeff is called to see McIntyre, but at the boat Linda walks off. Linda and Jeff get a divorce decree.
Sky finds Jeff sleeping in his office in misery because he can't forget Linda, who can't rest either. Sky gives Linda and Jeff drinks with the drug. Miss Wilson calls Sky, who learns that Dr. Schmidt (Sig Ruman) has no antidote and that Jeff has forgotten everything in the last six months. Jeff is smitten by Linda again, and she says she never met him before. Sky lets them fall in love again, but George tells Jeff to leave. Jeff and Linda make a date. Sky calls on Jeff, and Linda comes in. Jeff shows Linda the house, and the butler William (Halliwell Hobbes) brings Linda a nightgown. She is insulted, but Jeff asks her to marry. They drive, and the cop stops them, hearing the same excuse. They go to Judge Milliken, who says they can live together; but the cop demands a wedding. Jeff takes Linda home, and they tell Sky they got married. McIntyre comes in and praises Jeff for his new campaign. Jeff and Linda invite Sky on their honeymoon. Linda says she is going to have a baby, and Sky takes the drug.
This comedy uses a scientific fiction to cause irony
and humor, avoiding the issue that Jeff's advertising work is
disrupting his marriage.