The Well of Time. The Drath Series, #24

Scents of a Long-Gone Past Trinn stood, one paw held in space, as she breathed in the scents of the Well. Centuries of human lives lived in the Well filled her nose, carried in strata like slowly-formed sandstone. Such an old site, holding secrets of humanity's expansion into space. Trinn expected it to be amazing to explore and catalog. It was the exact sort of thing that she loved best as a historian. Until she went deeper into the Well and found a history that went much father back, all the way to the Drath's ancient roots back before they were people.
Then the question became how to explore this amazing, absurdly ancient site without destroying herself, the site and her human partner Camille.