It is always a joy to me to discover a piece of well-written, classic science fiction. Science fiction at its heart is the taking of an idea, usually some form of technology, and following it down the rabbit hole to wherever it leads.
In Clay, Bertauski explores biomites - constructs that are able to replace our body cells, our clay. But the government has mandated that you can only have 49.9% biomites. After that you are a halfskin, no longer human and subject to being terminated. The rule is enforced by a sinister AI known as MoTHER and her 'bricks' - human-like constructs made of 100% biomites.
With enough biomites you can also create a perception field around you, drawing others into your feelings and visions. It is this mechanism that enables the book to express the underlying themes of the nature of reality and what it means to be human.
As the book progresses, just as we feel we are understanding how things work, Bertauski throws another curveball and we realise that much of what we took to be truth was only the character's perception. Or, at least, we think so but we are never quite sure...
Even at the very end we are left uncertain. Hopefully all will be resolved in the next book - Motherland - but we will have to wait.
I discover to my delight that Bertauski has a least half-a-dozen other books (including the book before Clay - Halfskin - which I have yet to read). They have just made it to the top of my reading list.