Stumbled across this surprisingly fun tomb raider style mystery:
https://www.amazon.com/dp/B00JD121IG
Found it via @Clay’s post in the Assassin’s Creed thread. It’s actually the second in a series and follows the book Clay was recommending, but can totally be read out of order. Book #1 is also absolutely worth reading, but for different reasons; less tomb raiding and more tomb building with a bit of Bernard Cornwell style world/character building.