SciFi Wire reviews Sunless Countries
They say the book is "essential to Schroeder's artistic scheme and to the full enjoyment of this saga"
Nice review at Sci Fi Wire, full of words like "rich" "hectic" "dangerous" and "exciting." Not to mention "enigmatic" "exotic" and "bizarre." A book full of "perilous intrigue" that contains "revelations about Virga's place in the 'foam of worlds.'"
But the reviewer (Paul Di Filippo) is careful to make the point that while Sunless Countries fills in the blanks on the map provided by the other books, it can also be read on its own:
It might very well serve as a good gateway for newbies into the fascinating Virga cosmos, an enormous, air-filled fullerene balloon in the Vegan star system containing worldlets of varying size that center around the "sun of suns," Candesce. It's a Boschian landscape, full of rich cognitive estrangement, and Schroeder gets the most out of his conceptual playground, with taut prose and wild plotting.
In short, a very happy, enthusiastic review for the fourth book of "the Virga trilogy."