Although 'Blood Music' received more attention from the SF community , this is probably the book in which Bear set the standard for his subsequent work.
It's Hard SF/Big Science at its hardest, and in one sense can be seen as a 'Rendezvous with Rama' for the Nineteen Eighties.
Bear should also be applauded for his portrayal of female characters as in this and subsequent novels he places strong female characters centre-stage, in this case, Patricia Luis Vasquez, a young gifted physics student who is drafted in to solve the mysteries of the Stone and becomes important to the plans of all the factions involved.
The plot involves some complex physics and the concept of parallel universes.
It is always interesting to look at authors' views of the future once that future is past and gone. Written in 1985, Bear's future world has become a kind of 'alternate future' since perhaps no-one could have predicted that the abrupt fall of the USSR and the smashing down of the Berlin wall. Here, the USSR is still a superpower, and the Cold War very much alive.
Bear cleverly sets up the East/West ideological divides while Nuclear War destroys the Earth in the background, before bringing in the people of Earth's future. They live in Axis City, a vast mobile habitat which roams 'The Way' (the corridor which stretches along the infinity of parallel Universes) and which is itself divided along ideological lines between radical Geshels and orthodox Naderites.
It's a compelling and scientifically convincing novel, and one of Bear's best.