Two siblings fight over control of their family chain of grocery stores. Richard Gendreaux (John Carson) currently runs it.
His sister Lise Gendreaux will inherit half shares of the company when she turns 25 years of age which is sue in a few months time.
Richard wants to orchestrate a romance for his sister. If she marries before she is 25, she gets nothing. The target is cad Bob d'Anseval (Terence Alexander.) He has a prestigious name which will appeal to the snob in Lise.
However Bob has been writing dud cheques and Richard applies pressure for Bob to romance his sister quickly.
The story opens with Lapointe hearing a gunshot outside the Gendreaux residence but they quickly clear up the mess before Lapointe gets a chance to snoop around.
Maigret gives the inexperienced Lapointe time to snoop around in his own steam. Only for Lapointe to quickly find himself in trouble.
There was a good story with several flaws. Richard Gendreaux using his power and money to buy people off. Maigret seemingly unable to do anything about it.
The story lapses into comedy for some unfathomable reason several times. Especially during the fight scene at the end which is very odd.