Wealthy French lawyer Louis Martinot must travel away on business. He entrusts his friend, Paul Blythe, with a delicate task: to investigate the background of a young woman named Susanne Bergomat. If Paul deems her family suitable, he is authorized to propose marriage to her on Louis’s behalf. However, upon meeting Susanne, Paul immediately falls in love with her himself. To secure her for his own, Paul concocts a lie, telling Louis that Susanne's family is unsuitable because her mother is insane. Paul then proposes to Susanne directly and is accepted. The "villainous" deception eventually unravels, leading to a series of comedic complications as the truth about Paul's lies comes to light.