Maigret is woken by a call from his friend Dr. Pardon at 1:30 am, after they'd gone there for dinner on a freezing January night. Maigret went over, and Pardon told of a couple who'd appeared, the woman wounded in the back by a bullet. They'd disappeared after Pardon treated the wound, but without leaving any names, and after telling a fanciful story. Maigret learns the next day they'd departed from Orly for Amsterdam. He's called to the home of Félix Nahour, a Lebanese who's been shot in his home in the Avenue du Parc-Montsouris, and on his desk find a picture which matches Pardon's description of the woman, Évelina Nahour. The chambermaid, Louise Boudin, had found the body, but is uncommunicative. Neither is Évelina's maid, Nelly Velthuis, Dutch like her mistress, who claims to speak no French. Nahour's "secretary", Fouad Ouéni, also Lebanese, is taciturn, maintains he wasn't at home.
Maigret calls Amsterdam and arranges for Mrs. Nahour to be told that her husband has died and she'd needed for the reading of the will. Her boyfriend, Vicente Alvaredo, a wealthy Colombian student, also returns to Paris. Maigret interviews both of them, and Ouéni once more, and reconstructs the crime to his satisfaction. Évelina and Alvaredo had appeared to tell Nahour she was leaving him, whereupon he'd drawn a gun. At the same time Ouéni, who'd at one time been Évelina's lover shot Nahour, and Nahour's gun went off, wounding Évelina. Everyone denies all, and Ouéni is sentenced to ten years.
This report prepared by Dana Samson