I've been a big fan of Powers' work for a long time (more than my wife -- she couldn't make it through Expiration Date), and I have to say with this book and especially Declare, his previous offering, Tim Powers owns the Supernatural Spy Thriller sub-genre. OK, there aren't a lot of other people writing in that niche, perhaps Brian Lumley's Necroscope series, although that's more horrific than just supernatural, and perhaps a few of Koontz's early works... hmm... pair this with Lightning, perhaps, for a reading double feature?
TDTN deals with a hidden legacy of Albert Einstein, Charlie Chaplin movies, a supernatural branch of Israel's Mossad, a talking head in a box, a blind woman who sees through others' eyes and a thoroughly engaging story.
But it seems he's gone back to the same well a couple too many times. A lot of this book seems to rehash things he's written before: the legacy of a scientist and encounters with ghosts (Expiration Date), the whole middle-eastern spy stuff (Declare), time travel (Anubis Gates). But this is good. Really good. It's just that Declare was magnificent. The weaving of demonic forces, spies, bits of now and bits of then just worked so much better there than here.
If I had to pick two Powers books, I'd say Declare and Last Call, the others are all worth reading too (although Epitaph in Rust and The Scies Discrowned are an expensive two-pack hardcover for what were originally -- though now rare -- cheap paperbacks).