Suggest me a thriller?

Hi everyone!

Im looking for a book to send to a friend that lives overseas, and Im having trouble lining up our genre tastes. My idea is for us to each have a copy of the same book, and read it “together” as our own little book club.

To my knowledge, she reads crime/murder mystery, love story ish things (all the light we can not see, the light between oceans), history based fiction, and she enjoys Harry Potter.

My taste runs closer to fantasy and sci fi overall, but Im interested in more mystery based things and expanding my tastes. Some examples of stories/books Ive read and enjoyed are Altered Carbon (Morgan), Coraline (Gaiman), the Broken Earth Trilogy (N.K. Jemisin), and of course, Harry Potter.

I dont tend to read stuff from the “popular right now” section at Barnes and Noble (if thats helpful), they all feel… “plasticky” and forced to me. For example, Where the Crawdads Sing. A friend gave me PDF because they liked it, and two years later Im still mad about what a waste of time that thing was.

I also do not like stuff that has a lot of pro religion overtones, because I was raised agnostic and find this a bit grating. If it has to do with religious art/artifacts, or history of some sort thats probably fine, just no super religious characters and ideology if possible please. (Sorry! No offense intended!)

TLDR: Im looking for a book a long distance friend and I can read together. I was hoping for something more mystery or thriller related, because this seems to be where our reading tastes overlap most naturally. However, Im open to suggestions outside this genre category so long as they are not “bestseller” type books, and do not contain a lot of pro religion characters/conversations and etc.

An example of something we both like: Harry Potter

An example of something we both dislike: Stephen King

Thanks so much in advance, everyone! Hope your holiday season is going well so far!

by Bonhomie_111