Not quite Lord Peter
There was less to draw on this time from Sayers. Paton Walsh incorporated some "Wimsey papers" that Sayers had written for the Spectator magazine. These consisted of a sequence of mock letters between members of the Wimsey family intended to keep wartime spirits high. There's none of the intellectual crime-fighting sleuth in these papers. So that even those papers that are included in this novel feel very unlike how Wimsey appears in the main canon of text. The body of the novel is pure Paton Walsh, and it's extremely patchy. The tone didn't really work for me, some of the slang is strange, and feels forced. Interactions between characters, and the way they are portrayed also doesn't quite work, and the period feel is just not quite right. It's all off just by a whisker. For much of the first half of the novel, it felt like a pastiche, like someone trying to be someone else, and not quite getting the tone right. So a bad pastiche at that. Peter and Bunter are absent for the first half of the novel too, and I think this adds to the feeling of oddness.
And then suddenly, most unexpectedly, the novel takes off. The execution of the second crime (or rather thae way in which it appears to be executed) is pure Sayers - I could easily imagine this in an earlier novel of the series, then Peter returns, and he and Harriet go off on a sort of roadtrip to try to get to the heart of the crime. And this section runs wonderfully. I thoroughly enjoyed it: well described, reasonable characterisation, interactions between Peter and Harriet really work, crime starts to be unravelled - everything's wonderful, I was planning a positive review, and then, it just suddenly plummets again.
Back to pastiche, weak ending, weak crime - what a shame. I just found this novel plain irritating. There are odd moments when you can see how good it could have been, but the writing is generally weak, and there is some sloppy editing including one character who changes his name partway through.
If you're a Sayers fan, you'll want to read this just to read all the Wimsey mysteries, but it's not a good one. Although, perhaps not surprisingly for such a successful childrens' author, the Wimsey children are portrayed delightfully.