Tyler Trent, the young man whose letters are featured herein, describes one of his revealing visions as "a dream within a dream...." In a similar sense this is a book written within a book; the outer shell a brief account of the author's research in the cognitive and neurosciences, the inner core a summary of their correspondence extending from Tyler's undergraduate days to his untimely death. In effect the letters constitute his autobiography, edited in such a way as to highlight the unusual mental powers that originally inspired the author's research and helped him develop his well-known model of the brain processed, powers which he comes to believe may represent the next stage of human evolution. A singe "case study" like this can hardly prove such a belief to be true. But the highly original contributions to computer technology Tyler's intuitive gifts enabled him to make in his fifteen years of professional life, plus the fact that throughout history many of our most influential ideas have originated in the same way, strongly suggests that it may be. The avalanche of information that threatens to engulf us is certainly a challenge comparable to the climactic changes of the ice age that forced the evolution of homo sapiens; and if exploiting the existing resources of the subconscious minds is a possible way of coping with it, then surely, as the author suggests, the brain mutation which makes this possible should be encouraged to spread more rapidly.