A couple of titles in the Hidden Legacy series by Ilona Andrews have dropped to £0.99 at Kindle UK, possibly as a lead-in to the upcoming
Emerald Blaze, set to come out towards the end of August.
Wildfire is the third book in the series and finishes the story arc for Nevada Baylor (and Rogan):
https://www.amazon.co.uk/dp/B01MDTF1A9
Diamond Fire is a novella set at the time of Nevada and Rogan's wedding, which gives a bigger role to Nevada's sister Catalina, who is the protagonist of the next story line:
https://www.amazon.co.uk/dp/B07BK3M7V7
BTW, in looking at these I noticed that
Emerald Blaze is only £2.99 to pre-order in the UK, which is a lot better than the $6.99 it's priced at in the US. I'm not much on pre-orders usually, but that's a pretty good price...