While having dental work done, Jimmy inhales too much gas and begins believing that he is a detective. He sets out to capture a gang of thieves who robbed Jean's uncle's bank.

A scientist discovers a death ray and locks it in a box, giving the key to his daughter, who soon finds herself hunted by criminals looking to steal the deadly mineral.

Carlotta Darley (Dean) is engaged to Homer Carleton (Crosby), but regrets that Homer is not as tall and handsome as the butler Peter (Kerry).

Jude Hunter (Katherine Hughes) is a committed musician who is in the middle of preparing for the biggest and most important performance of her life. When mysterious, unprecedented, and seemingly connected deaths occur as the competition draws near, she begins to feel unsafe, thinking that she might be the next target.

Mr. Schmidt's costume store is bankrupt because he spends his time on Rube Goldberg-style inventions; the creditors send a young manager who falls for Schmidt's niece Louise, but she'll have none of him. Schmidt's friends Ted, Queenie, and some goofy firemen try to help out; things come to a slapstick head when Louise needs rescuing from a fire.

Freddie, a rich young idler, meets Julia Harrington, a wealthy social service worker who runs a haven for reformed criminals. By telling her he is a hardened criminal, he is allowed to stay at the mission.

In Puritan Boston, seamstress Hester Prynne and kindly Reverend Arthur Dimmesdale fall in love. After Dimmesdale must go away for a time to England, he returns to discover that Hester has given birth to their child and is the focus of local censure.

Bank cashier Ramsey Latham is sentenced to prison for violation of the banking laws. On his way to the penitentiary, he encounters Hilary Kenyon, a young girl who speaks encouragingly to him. Later he is surprised to discover that Hilary is also a prisoner, having been found guilty of manslaughter for killing a man who attacked her.

Although laborer Joe Mercer loves factory girl Katinka Jenkins, she agrees to become the mistress of Lindsay, the mill owner, in order to escape dire poverty and cruel parents. Katinka sends Lindsay's money to her family, but eventually, he finds himself unable to pay his employees, and only under Joe's influence are the men prevented from striking. Reformer John Strong, who loves Katinka's sister Olivia, visits Katinka to request that she cease her disgraceful dance performances, but he soon submits to her charms and is passionately embracing her when Olivia enters the room. Katinka then learns of the situation at the mill and realizes that the compromise of her honor has ruined more lives than her own.

Judge Randolph Legarde becomes a dual personality when he is kicked in the head by a horse.