New York schoolmarm Hildegarde Withers assists a detective when a body of unscrupulous stockbroker Gerald Parker suddenly appears in the penguin tank at the aquarium.

There are plenty of guilty secrets at the school where Hildegarde Withers teaches. When she finds the body of the pretty music teacher, she calls in her old friend Inspector Piper, who promptly arrests the obvious suspect. Clues multiply and everyone looks suspicious as Piper and Miss Withers continue their battle of the sexes.

An amateur sleuth suspects foul play when a fellow passenger on a seaplane suddenly dies. The third and final film with Edna May Oliver and James Gleason as the astute schoolteacher Hildegarde Withers and the New York Police Inspector Oscar Piper busy solving crimes.

When the body of Violet Feverel is discovered on the Central Park bridle path, Inspector Oscar Piper is about to declare her death accidental from a thrown horse, until his friend and amateur detective Hildegarde Withers locates the horse and discovers blood on the horse.

A priceless Cellini silver cup is stolen from a local museum with both Hildegarde and Oscar on the case.

Hildegarde Withers and Inspector Piper try to solve a murder while attending a popular Broadway show.