André de Kerdec, a young lawyer buys an old parchment in an antique shop and discovers that a treasure is hidden in the bedroom of Artémise, an old maid who owns a manor. He manages to be hired as her chauffeur by Artémise and sets about looking for the treasure. During this time, he falls in love with Lucie, the old spinster's niece. But the trouble is that Artémise develops a crush on André...!