The second bunch of Maigret novels have a more relaxed and expansive…
The second bunch of Maigret novels have a more relaxed and expansive feel than the first cluster. At times the landscape itself is sunnier. (This is a powerful technique in fiction, more so than readers consciously notice. Christopher Sykes once asked his good friend Evelyn Waugh how it was that one of his earlier novels, apparently light and humorous, had an undertow of melancholy. Waugh said he had done it by keeping the weather in the book grey and rainy.)
LRB
https://www.lrb.co.uk/the-paper/v42/n11/john-lanchester/maigret-s-room