I like this best of all the Sayers books even though it is not a Lord Peter story. It is also the only book written with a co-author. Not sure if either of these things is why I like it. Just find it very interesting and different.
Very enjoyable non-series mystery written by a renown author. The information on the event and the solving is revealed by way of letters, testimony in the trial, flashbacks. Setting is England of the late 1920's. Sample of the pithy views of some of the characters: "If hotel life is your notion of happiness you ought to go and live in America." pg 28.