Powell and Loy are Steve and Susan Ireland, a married couple who are celebrating their fourth anniversary. They are happily married to an absurd degree, with the only fly in the ointment being Susan's annoying mother, Mrs. Cooper, who hates Steve.
Naturally, they break up. A series of comic misunderstandings on their anniversary, mostly dealing with the presence of Steve's old girlfriend Isobel (Gail Patrick), now their new neighbor, lead to Susan walking out. She takes up with another neighbor, champion archer Ward Willoughby (Jack Carson), while waiting out the necessary period to get a divorce. Steve is helpless to prevent the divorce, until his lawyer reminds him of one legal loophole: a spouse judged to be insane cannot be party to a divorce. Comic hijinx ensue as Steve sets out to convince the world that he is crazy in order to hold on to Susan.
Elisha Cook Jr. has a small role as the elevator operator.
- As You Know: Mrs. Cooper identifies herself to the audience by giving Steve the ugly rug and saying "Best love from mother-in-law."
- Buffy Speak: Susan describes Ward Willoughby as a champion "bow-and-arrower".
- Chekhov's Gunman: Steve's insanity act at the party impresses a Funny Foreigner. The funny foreigner is later revealed to be one Dr. Klugle—the psychiatrist who is head of the "Lunacy Board" that will determine if Steve needs to be institutionalized.
- Diagonal Billing: How Powell and Loy are presented in the opening titles; this was one of the first movies ever made to use this trope.
- Disguised in Drag: Having escaped from the insane asylum, and being hunted by the police, Steve dons women's clothing and claims to be his own sister. He shaves off his mustache in the process, marking the only time in William Powell's 30-year movie career where he appeared without it.
- Divorce Is Temporary: Steve goes to all sorts of wacky madcap extremes to save his marriage to Susan.
- Elevator Failure: Steve gets trapped in an elevator with Isobel (and the elevator operator, played by Elisha Cook Jr.). It's an extended comedy sequence in itself as Steve gets his head stuck in the elevator door and Isobel has to clamber up over him to get out, but it's part of the whole breakup as Steve's succession of white lies winds up convincing Susan that he cheated on her.
- Fanservice: An extended sequence in the Ireland home where Susan is wearing nothing but a snugly fitting nightie.
- Gone Horribly Right: Steve gets more than he bargained for when his ruse of feigning madness, meant to stall the divorce, gets him chucked in an insane asylum.
- Happily Married: Absurdly so, as Steve and Susan are the picture of wedded bliss along with a thriving sex life, which makes it surprising when they are broken up so rapidly.
- Naked People Are Funny: Steve accidentally makes his crazy act more convincing when, while clad only in a sheet, he tries to retrieve his watch (a bird flew away with it), and falls out of a tree, losing the sheet in the process.
- No Name Given: Susan's awful mother is never named, even "Mrs. Cooper" comes only from the credits.
- Obnoxious In-Laws: Mrs. Cooper, the worst sort of meddling nosy mother who belittles Steve constantly while giving him awful gifts (the ugly throw rug she delivers in the opening scenes proves important) and generally getting in the way of Steve's relationship with his wife. When the opportunity pops up she is only too eager to force Steve and Susan apart.
- Old Flame: Steve's old girlfriend Isobel, who is now married (she appears to be a Trophy Wife) and is one floor below in the apartment building. She is only too eager to start things back up again with Steve despite both of them being married to others.
- Operation: Jealousy: Susan sets out to kiss Isobel's husband to make Steve jealous, but winds up going to the wrong apartment and meeting Ward Willoughby.
- Romantic False Lead: Ward Willoughby, present to be an obstacle to the reunion of Steve and Susan.
- Rom Com Job: Steve's an architect.
- Screwball Comedy: Wacky humor based on comic misunderstandings, as Steve blunders into a divorce suit and then has to scramble to win his wife back.
- Sleeping Single: Like most movie couples of the era Steve and Isobel sleep in separate beds. It's particularly noticeable here as the whole opening sequence has Steve quite obviously trying to get rid of everyone in the house so he can have sex with his wife.
- Uncle Tomfoolery: Some racist even for 1941 humor as Steve starts pretending he's Abraham Lincoln, and the black man behind the hat check counter believes him.