Tommy and Tuppence Beresford are Partners in Crime, or rather partners in crime solving, and must demonstrate their deductive skills in a wide range of confounding cases after agreeing to take over Blunt's International Detective Agency

A fairy in the flat -- A pot of tea -- Affair of the pink pearl -- Adventure of the sinister stranger -- Finessing the king -- Gentleman dressed in newspaper -- Case of the missing lady -- Blindman's bluff -- Man in the mist -- Crackler -- Sunningdale mystery -- House of lurking death -- Unbreakable alibi -- Clergyman's daughter -- Red house -- Ambassador's boots -- Man who was no. 16