[William Cloud Hicklin]

As in, actually by JRR Tolkien, not just about him.

The Nature of Middle-earth is a collection of late writings, in both the metaphysical and literal senses of the title: Tolkien's musings on the cosmology of his creation, as well as its biosphere. The collection, edited by Carl F. Hostetter (our own Aelfwine), was authorized by the late Christopher Tolkien before his death and can be viewed as a sort of 13th volume of The History of Middle Earth.

Scheduled for release in the spring of 2021.