[sufue]

Knave of Diamonds is the nineteenth and most recent (2025) in Laurie R King's Mary Russell/Sherlock Holmes series. It's doing the £0.99 thing in the UK today, although somewhat unusually, it doesn't show up formally in the Kindle Daily Deal. Still, I'd assume it's for today only, which is not a lot more hours in the UK, and grab it now if you want it. And it's discountable at Kobo...

Kindle UK: https://www.amazon.co.uk/dp/B0DYK8PF2R
Kobo UK: https://www.kobo.com/gb/en/ebook/knave-of-diamonds-1

Spoiler:

When Mary Russell was a child, she adored her Uncle Jake, the black sheep of the family. But she hasn't heard from him in many years, until her ne'er-do-well relative presents himself at her door with an abundance of problems for his clever niece to deal with. Not the least of which is the reason the family rejected him in the first place: his involvement in the infamous disappearance of the Irish Crown Jewels from Dublin Castle in 1907.

It was a theft that shook a government, enraged King Edward VII and threatened the establishment. Juggling conflicting loyalties and international secrets, Russell is entangled in the web of a case that not even the great Sherlock Holmes could solve.