A Glancing Light is the second in Aaron Elkins' too-short IMO Chris Norgren series. It's on sale right now for $0.99/£0.89 in the US/UK, and it's discountable at Kobo. These are Open Road titles, but go on sale more often at $1.99, so I thought I'd go ahead and post the lower price...
Kindle US:
https://www.amazon.com/dp/B00J84L3LE
Kobo US:
https://www.kobo.com/us/en/ebook/a-glancing-light-1
Kindle UK:
https://www.amazon.co.uk/dp/B00J84L3LE