Andrew Blake was ""the man who came back from the stars."" Discovered encapsulated, frozen in a wandering asteroid he has been revived and returned to earth where only vague memories of a past some, two hundred years before provide a clue as to why he was deliberately, entombed. But then there are the two alien entities lurking within his consciousness. Mr. Simak uses an exciting projection of biochemistry to construct a smooth adventure story. But sophisticated readers may balk at the pat Perfect ending.