After the truly appalling flushing-down-the-lavatory-of-the-licence-fee that was The Liberty Bar, any 50 minutes of television meeting the most modest broadcasting standards is a welcome contrast and this episode does qualify.
The plot is Simenon trying to do a bit of a Christie with a technical element to the solution of the murder but he lack's the Queen of Crime's skill in such matters and plausibility is strained somewhat.
There is just about enough light and shade thanks to Ewen Solon's reliable portrayal of the jovial Lucas but there is too much of the amateur comic cuts about some of the minor characters, in some cases due to performance issues, in others because of a lack in the script. Charles Lloyd Pack plainly had the ability to make something wittier of the hotel proprietor, if he had the lines whereas Wilfred Bramble shows himself to be the one-trick pony of Albert Steptoe as a supposedly Jewish newspaper seller who can't make his mind up whether he comes from Poland or Limerick and makes a pretty ham-fisted mess of both acts.
As usual in the early episodes a lot rests on Davies to carry the whole thing but it is not a bad one.