Who is Cliff Doe?
''Giebeig says she thinks about the man often and even recently started to read the “Phases of Gravity,” the book that was found with him when he died, thinking that maybe it would reveal something about his personality or his mindset when he died.''
This is the book found with the UID's possessions, FWIW..
''Phases of Gravity''
https://www.amazon.com/Phases-Gravity-Dan-Simmons/dp/1596064161
''Richard Baedecker, the aptly named hero of this extraordinary novel, is a man adrift, searching for a lost sense of purpose. A former astronaut, Baedecker once walked on the moon, briefly escaping the tidal pull of gravity itself. Sixteen years later, gravity and other entropic forces have overtaken him. His marriage has ended. His professional life has grown increasingly meaningless. His relationship with his only son has all but disintegrated. At this critical moment, against the unlikely backdrop of Poona, India, Baedecker encounters a remarkable young woman named Maggie Brown, who will point him toward the "places of power" he has left behind and help him rediscover his essential self.
Phases of Gravity is a novel about the power of dreams and the possibility of second chances, about journeys remembered and newly undertaken. It is also, like so much of Dan Simmons's work, a deeply affecting reflection on "the richness and mystery of the universe." Moving effortlessly from the surface of the moon to the small towns of the American Midwest to the sacred Black Hills of South Dakota, and filled with wisdom, unexpected turnings, and flashes of irreverent wit, Phases of Gravity is, by any definition, a major work, the kind of durable, fully realized creation that only a master novelist could produce.''