Loving the cover text from the S&S edition -- the back features a snappy bio of Millen Brand, who at the time was more or less an unknown. Interesting facts! About Brand!:
He is now thirty years old. He plays chess occasionally, but is indifferent about most games. He is no automaton. ... he has, according to his wife (who is Pauline Leader, author of And No Birds Sing), an irritatingly even disposition.
Will probably scan/write more about this later when I collect my thoughts. New York Review Books reprinted it in 2010 -- if you're interested in a work that begins with a riveting escape from a mental hospital, this is for you!