The Chronoliths by Robert Charles Wilson

The Chronoliths takes place in the near future. Scott Warden, the narrator, is living in Thailand with his wife and young daughter when the first of the Chronoliths "arrives" near where he has been living. Chronoliths are huge and strange monuments of unknown material, that arrive suddenly bearing the likeness of Kuin or a testament to his conquests. Many stories high, they are of some sort of blue glass-like substance that can't be broken (even with atomic weaponry) and that supplants all that is in their place.

Scott Warden follows his wife and daughter to the United States, but too late to save his marriage. He spends the next several years working as a programmer and seeing his daughter Kaitlin on weekends. Eventually, his wife remarriage a prosperous man who seems to be a nice enough guy, if a little pompous.

About five years after Scott's return to the U.S., he is summarily fired from his job, only to be hired by an old college professor Sue Chopra. Sue is a brilliant theoretical mathematician and has been working on the problem of the Chronoliths. She hires Scott to work with her, in part because she believes that a number of coincidences (Scott and a friend being present when the first Chronolith appeared, Scott being a former student of Chopra's, etc.) have meaning, if only the problem could be viewed from additional dimensions.

Another ten years pass and more Chronoliths have appeared throughout the world. People in many regions have become Kuinists, adding to the instability of governments around the world. Young people in Kuinist groups are prone to going on "Haj", by which they mean setting up camp where a Chronolith is expected to appear (by this time scientists can predict the appearance of a Chronolith by preceding radiation.) Scott's daughter Kaitlin has joined a Kuinist youth group, in part because her stepfather belongs to a group for business reasons, and has disappeared.

Scott gathers information about the youth group Kaitlin has become involved in, and goes looking for her in Mexico. In the course of seeking out Kaitlin, he takes up with a woman whose son is also on the Haj, Ashlee. In Portillo, Scott is able to find and rescue Kaitlin, but Ashlee's son is apparently lost.

More years pass, the world grows ever more unstable, and Sue Chopra believes she has found a way to destabilize a Chronolith. It is during the outcome of this attempt that the penultimate action of the novel takes place, with only a few final pages to round things up.

This was an interesting book with an intriguing premise. The characters are mostly believably human, although not so well grounded as the characters in Spin, by contrast. Overall, worth reading.