Unfortunately at the moment Goodreads has presented both the original Simon Brett novel and the modernized full-cast radio drama as a single entry forcing me to combine my thoughts on the two versions of the story.
Though the radio play does update the setting and transform several of the characters noticeably, the essential points of the story are identical to those of the novel. Fortunately that plot is one of Brett's best, featuring a twist that while not original, is so well executed in both versions as to be very satisfying.
In both versions Paris finds himself in work alongside an actress who has been given a leg-up by a showbiz magnate who she has been sleeping with. Unfortunately things between the actress and her lover have become difficult and so, distraught, she turns to Paris to try to intervene and make contact with him. In order to do that though Charles will have to find some way of getting in touch with him...
Brett's novel is perhaps the best of his Paris mysteries, doing a great job of establishing Charles' character and finding a believable way to get him involved in solving a mystery. Like all of his novels, it is a pretty quick read, and to my tastes, one of his funniest.
The audio play is a little more drawn out, lacking some of the novel's tension. On the other hand it manages to draw even more humor out of the story, helped by some superb performances - especially from actor Bill Nighy who gets some very funny domestic moments interacting with his long-suffering family.
Though both versions are enjoyable I would probably recommend the latter more to those who are curious about the mysteries as some of the novel's humor and topical references feel dated.