Provenance: I only read this about 10 years ago. I didn't read it when it came out in part because it released in one of those sections of my life where I didn't read a lot of new fiction. I had graduated, got a "real job" as civil engineer, was laid off from that "new job" and had found another job in Wisconsin, moved, got married, and eventually was hip-deep in Dragonlance and Marvel Super Heroes. So I was, like, BUSY at the time. So lay off, OK?
Anyway, I missed the boat and the book, though friends recommended it strongly over the years. And I finally came across a copy in 2009. I know this because I have the receipt as a book mark, from the Barnes & Nobles Booksellers at the University Village (now no longer there). Also in the book was a take-out menu from the Delfino's (really good Chicago Deep Dish), and a flyer for a Butoh performance at the Richard Hugo House that I never attended. So I have a good idea of the time and place for this one.
Review: I'm sorry I missed it the first time around, but happy I caught up with it later. I've gone on about playing fair with the reader, and Powers does this in spades. But first, let me give you the back story:
A group of Egyptian cultists back at the start of the 1800s try to summon their god to drive the English out of Egypt. They don't succeed, but do manage to punch a number of discrete holes in the timestream. In the present day, a dying millionaire discovers those holes and sees them as a way of time travel. He hires Brendan Doyle, English professor and expert on an obscure author named Ashbless to lead a group back in time to a lecture by Samuel Coleridge. Of course the millionaire has a secret agenda, as almost every does - well, everyone except Doyle.
Things go casters up in the past, and Doyle is kidnapped and stuck there, with multiple factions all with different aims hunting for him. Now, the book does two things I like - one is how Powers handles the man from the future in the past, and the other is writing a book in which time travel is inelastic while still maintaining suspense.
For the first part, there is a classic bit of SF from L Sprague DeCamp called Lest Darkness Fall, about a modern archaeologist who finds himself trapped in Late-Roman Empire Times. Using his 20th Century knowledge of the past, he proceeds to turn things around, rally the Ostrogoths, and stave off the Dark Ages. DeCamp's protagonist is the capable, competent, professional that inhabits such stories.
Doyle? Not so much. His knowledge of the future doesn't help, and his ineptness with his current present results in him being reduced to starvation and begging almost immediately. Far from being the competent nigh-omniscient, Doyle is overwhelmed by his new situation. Things he knows from the future turn out to be untrue, and things get worse as the other factions move in.
The other thing I liked about the plot is that it works off the fact that time travel is inelastic - you can't change the past. No bumping off the Emperor, because your history will not allow it. Now, writing a book with the protagonist having agency in a deterministic universe is a bit of a challenge, but Powers pulls it off neatly, because a lot of specific knowledge gets lost over time, and the escapes lay in the details. Doyle knows his "death date", which cannot be changed, but if and how he avoids it is part of the charm of the book.
Yeah, I can see how this hit a lot of people hard when its first came out. It is tightly written, and plays by the rules while opening the doors to some truly strange occurrences (which we don't know about tucked away safely uptime). We have werewolves, we have ancient gods, we have wizards so evil that they cannot walk on the earth (one has stilts). We have body swapping and simulacra. We have history and secret history.
There feels to be long standing effects on gaming Shadowfist/Feng Shui (card game and RPG set in the same universe) uses the idea of multiple fixed time portals. World of Darkness embraces the entire secret history (though there are other volumes of this ilk). And the entire vibe of Egyptian Cult and 19th centruy England has a very Masks of Nyarlathetop feel to it. And while it does not make the list of various Appendix N's, it feels like a D&D adventure in many ways. So I'm going to hazard a guess that this has book, combining fantasy with strict adherence to history, had a definite impact on gaming.
It is worth digging out all these years later, so go take a look.