I don’t know if there’s a through narrative holding all of these Maigret novels together. As this one begins he’s two years into his retirement. Was this his second retirement? I wonder if anyone has worked out a Maigret chronology. They probably have but I’m too lazy to look for it. [Note: This is an issue that’s later addressed in Maigret’s Memoirs, where “Maigret” complains about the way Simenon jumbles up the chronology of his life.] I also wonder if the mention of an earlier investigation in the Haute Seine was a reference to Lock No. 1. How well do these books hold together?
In any event, Maigret gets tempted out of retirement here not by the big pile of money he’s offered but because the case interests him. Soon, however, it disgusts him. It’s yet another case involving “the social mechanism,” a.k.a. “the dodgy dealings of those who [grow] rich.” Ernest Malik is one such riser, and as so often happens (see what I said in my notes on The Cellars of the Majestic) he’s done it in ways that at best show a lack of scruple.
The crimes are described as a “vile business, which, from start to finish, was all a filthy matter of money.” If you’re born with money you’re decadent; if you have to get it you’re a crook. Either way, money just provides a sham façade to hide family skeletons behind. “For that is all there was behind those beautiful houses with their immaculate gardens: money!” Note how, at the beginning, the lady who hires Maigret mistakes him for a gardener. Detective or gardener, in either role he’s just cleaning up after rich people. I’m not surprised he’s sick of it.