Based on one of the better of the more psychological of Simenon's stories, this one is well done, benefiting from the series's increasing use of filmed inserts of location scenes. Unusually, some of these have dubbed dialogue which does help with the feeling of momentum even if the synchronization is less than perfect.
As the story was adapted in both the Gambon and Atkinson versions one can make some interesting comparisons, notably in the location sections on the streets of Montmartre . Although Atkinson was truly awful as Maigret and his series pretty poor in most other respects, one would naturally expect his huge budget and modern technology to eclipse something made in 1962 when it came to locations but no; the atmosphere and tension here is the more gripping. Even the Gambon version doesn't quite match the Davies version in this area.
In the the office-based investigation Davies again eclipses Atkinson in dealing with the psychology of the main characters but doesn't do as well as Gambon. With a longer running-time Gambon did have an advantage in developing interaction with the characters, particularly the main suspect's wife, but Davies would still have been helped here by better scripting and a performance of more depth than is on offer from Jacquline Hill.
A walk-on part by Mary Hignett as head of the women detectives section might interest anyone familiar with All Creatures Great and Small as she was Mrs Hall, the housekeeper.
Overall an enjoyable episode, a very long way from the standards of series 1.