3.5 leaning heavily towards 4 stars. Sadly didn't get it all the way.

Good interesting subject for a story for sure. Roots of trees talking, mining, caving, rock climbing. Just needed diving and cycling for a full deck ;) Science, hiding waste from the future, folklore, myth. All subjects that kept me reading, as I enjoy learning about this.

The question "are we good ancestors?" Go me thinking about how we are now and what we are leaving behind.

But some of the side notes and anecdotal, where at time a bit eh, why? Along with the a bit over the top flowerly writing. And a couple of times I was thinking have I pressed the back button and skipped back to a chapter I had already read, as he repeated some bits.

Though that said I did really enjoy reading about the Paris Catacombs, as I have walked and crawled these tunnels before a few times.. Though I do remember the mud and water than Robert, he clearly forgot ;)