I just finished “The Charlemagne Pursuit” by Steve Berry which is such a fun thriller to read. It’s the 4th in the series featuring Cotton Malone who is a “retired” military officer, now a bookseller. He gets involved in these wild adventures looking for Templar treasure, the library of Alexandria, and more.
If you liked “The Da Vinci Code”, you would like these as well. They’re historically researched so they’re based on facts which makes them more fun. I enjoyed reading Berry’s Writer’s Notes at the end of the books first since he explains what’s fact vs what’s fiction, and I find that fascinating.