The Singing Sands is the fifth Alan Grant book by Josephine Tey, or the sixth if you count Grant’s appearance as a minor character in
The Franchise Affair. It’s on sale for $2.99 in the US right now. Of course, if you are lucky enough to be in one of the countries where copyright laws already put
The Singing Sands in the public domain, you can download for free from Faded Page or Project Gutenberg Canada, and probably some other PD websites too.
Kindle US:
https://www.amazon.com/dp/B0868T6YCD
Kobo US:
https://www.kobo.com/us/en/ebook/the-singing-sands-19