Nancy Bilyeau’s three Genevieve Planché historical mysteries, two older and one not-yet-out, are all on sale for $0.99/£0.99 right now in the US/UK. The email I got from Joffe books with the sale info indicates the prices will be good for this week only…
The Blue, #1
Buy at Kindle US | Kindle UK
The Fugitive Colours, #2
Buy at Kindle US | Kindle UK
The Versailles Formula, pre-order (coming on 17 April, 2025)
Buy at Kindle US | Kindle UK
Please note, however, that there were earlier versions of both The Blue and The Fugitive Colours, from a different publisher, Endeavour, who went out of business a while back. And those versions went on sale fairly often. So check your library carefully before you buy!
The Blue is free right now at Kindle US and UK. The links in the OP are still good…