I think the problem for me is that I don't like Josephine Tey - the person, I mean. She's a raging snob, for a start. Her Scottish maids, waitresses, etc, and the English landlady, not to mention the friend of the murder victim, who pops up in the middle of nowhere, are all depicted as rather inferior to people with servants. There's also a very dated snobbery about Scotland. It's taken for granted that the hotels will be awful, the food will be worse, and that it's a place to escape from. The nationalist, wee Archie, is such a grotesque caricature, with his dirty unwashed clothes and his'vile' Glagow accent, that I wonder why she put him in the book - he isn't relevant to the plot, after all. The same irrelevance applies to the fragrant lady something-or-other, who has no purpose whatsoever. Tey seems happier altogether when Grant returns to London, where there are nice people with servants - Grant has his 'housekeeper' who is clearly of an inferior 'class' bur at least is comic.
The plot, too, is poor, To say it is contrived would be an understatement. It isn't even contrived. There's a long and pointless session in the Scottish Highlands followed by some wandering around Europe for undisclosed purposes, then at the end the villain conveniently has the grace to send a long letter of confession to Grant, for no reason that I can fathom.
A book I endured, hoping for something interesting or striking to happen. But it didn't. No more Tey for me! It's off to the charity shop for this one.