Null-A Three

Null-A Three, usually written Ā Three, is a 1985 science fiction novel by A. E. van Vogt. It incorporates concepts from the General semantics of Alfred Korzybski and refers to non-Aristotelian logic.
The novel is a continuation of the adventures of Gilbert Gosseyn from "The World of Null-A" (1945) and "The Pawns of Null-A" (1948).
Plot.
Gilbert Gosseyn wakes to find he is Gosseyn Three, in telepathic contact with Gosseyn Two. One of the spare bodies used in his reincarnation machinery was found and forced to life by the approach of an immense space fleet from another galaxy, manned by the primordial ancestors of man, gripped in an eon-long war with mutants equally old. The space-fleet is ruled by an unstable youngster who seems to possess many of the same powers, including a double-brain, as Gosseyn.
Gosseyn must school the youth in Null-A sanity, save the Earth from a cabal of gangsters and businessmen who oppose the return of the Games Machine, discover the secret reasons behind the endless horrifying war, and stop the intrigues of Enro the Red to return to power.
Reception.
Dave Langford reviewed "Null-A Three" for "White Dwarf" #64, and stated that "The book can only be read as parody or in a spirit (several bottles' worth) of overwhelming nostalgia for the 'Golden Age'."
Many critics regard "Null-A Three" as the weakest of the Null-A books, and the estate-authorized Null-A sequel "Null-A Continuum" ignores its events.