Okay, I can see where this is compared to the X-Files. The MC Nolan, while not as crazed in his search for "the truth" and "the truth" being aliens per se, is certainly open minded and a believer in spooky anomalies that he is willing to try and find for his Youtube show The Anomaly Files. Which leads him and his team to a weird cave in the Grand Canyon.

Indiana Jones? There is a giant ball that may or may not roll through a cave. But it's the "group of scientist/explorers being killed one-by-one" trope (which I love) that makes me think of this book as more Crichton-esque, but without the in-depth science within the science fiction.

I don't know if I would read this as a series, but this book does well enough on its own and was fun to read. Definitely a great page-turner!

Spoiler

The second to last chapter was very reminiscent of Well Manicured Man or someone from the Syndicate meeting Mulder on a park bench to tell hi, to stop his pursuit of the truth and forget everything he saw.