Eon   by Greg Bear

First some shallow observations: the book is full of typographical errors, which must be a production problem as the author is clearly capable of impeccable work; the chapter breaks are erratic, sometimes demarking a single point of discussion of less than a page in length, and other times embracing several demarked sections of text covering the actions of lots of disparate groups of people; the book is undoubtedly rooted in Arthur Clarke's two big works. The book shows its age by revolving around the Cold War conflict of the 1980's, but this is the only betrayal. The rest is pure imagination.

The real strength of this book is in that the science fiction keeps on coming. Most writers would have left the science off at the introduction of a hollow comet with an infinitely long interior and wound some interesting tale around it, but Greg keeps the ideas coming. There's a singularity running the length of the chamber, there's an alien city built around the singularity, there are alien cities on the inside surface of the cylinder, which also sprouts holes to other universes. Greg leaves nothing unturned or unfinished for the reader's dismay: he goes down inside the universal gates, and he develops a rich history of the civilizations which have lived in the comet, replete with complex conflicts, ideologies and politics. Nothing in the book is inconsequential; everything has a reason and is explained.

The central character is a mathematician brought from earth to attempt to explain the time-space geometry. While she is working, she realizes that the comet is from earth's own future, and furthermore that in the immediate future a global nuclear war will flare on Earth and leave a long winter. Sure enough, this happens, but then the mathematician realizes she can retrieve the situation with some desperate manipulations of time and space. This does not work out exactly how she had predicted, leaving a peculiar ending.

At no point is this book either predictable or unsurprising. It continues always to introduce new science, and new turns to the storyline. It is completely engrossing the whole way through.