Paul Kemprecos is probably better known for his collaboration with Clive Cussler on the thriller-ish NUMA files series, but I’ve always liked his Aristotle Plato Socarides (“Soc”, which nickname you’d probably use too if you had that name) series, which is a more traditional PI series. Now The Mayflower Murders, which is the fifth in the series, is on Kindle Countdown in both the US and UK ($0.99/£0.99) for about a day more.
Cool Blue Tomb is the first in this series, and it’s on sale for $0.99/£0.99 at Kindle US/UK. (It’s a Countdown deal good for almost two more days.)
Kindle US: https://www.amazon.com/dp/B007MJLPDI
Kindle UK: https://www.amazon.co.uk/dp/B007MJLPDI