After an embezzling accountant leaves her penniless, ex-model Maddie Hayes decides to sell the few failing businesses she still owns, among them a detective agency. But private eye David Addison wants to keeps his job, so he persuades a reluctant Maddie to form a partnership. Their first case gives them little to go on: Maddie gets a broken watch from a dying man.

Dave and Maddie face a difficult situation when they have to tell their client that the son he hired them to find is a notorious contract killer.

Maddie believes that a client's design secrets are being pilfered from the astral plane by a psychic.

Maddie becomes infatuated with a radio talk-show host who has apparently been murdered while he was on the air.

Maddie and Dave get trapped on a train filled with mystery buffs when they try to deliver Agnes on time for her big weekend solving a make-believe murder staged by a famous author.