Twenty Plus Two (1961)

Federal agent Alexandra Barnes believes that Catherine Petersen is a serial killer who marries rich men and then murders them for their money. But since Catherine is seemingly a master of disguise and has multiple identities, Alexandra can't prove anything with conventional detective work. With no other option, she goes undercover, pursuing the same man as Catherine, and hoping that Catherine will slip up and reveal her true identity.

High society sleuths Nick and Nora Charles run into a variety of shady characters while investigating a race-track murder.

Former prosecutor-turned-therapist Hailey Dean is a powerhouse, Mensa bright, and acutely observant. During a tragic week, one of her patients loses her parents to separate fatal accidents along with millions of dollars that has seemingly vanished into thin air. When the police begin to question Hailey's patient, shes knows she is innocent. But who is the culprit?

When a mysterious force begins to disrupt their big summer fun, Noah and his friends team up with a retired police detective to embark on a monstrous adventure to save their island.

Jane Marple solves the mystery when a local woman is poisoned and a visiting movie star seems to have been the intended victim.

Not even the joys of parenthood can stop married sleuths Nick and Nora Charles from investigating a murder on a Long Island estate.

Four friends search for the answers to a series of deadly text messages killing students at their high school.

Adrian Messenger, a famous writer, asks his friend Anthony Gethryn, a former British agent, to help him investigate the whereabouts of the people who appear on a list, without asking him the reason why he should do so.

Hannah Swensen is thrilled when she is chosen as a guest for the first Eden Lake Dessert Bake-Off, but when fellow judge, Coach Bishop is found murdered, Hannah once again takes it upon herself to find the killer.

On a trip to visit his parents, detective Nick Charles gets mixed up in a murder investigation.