Thomas Mullen's
The Revisionists (Mulholland Books, 2011) is a fast-paced, highly intellectual thriller with all sorts of interesting things to say about the intersections of the past, present and future and the ways in which individual actions and events shape history. Our main character, Zed, is an agent from the future, sent back in time to ensure that all the nasty events of our own day still happen so that the humans of the future can live in a society made perfected by learning from the mistakes of the past. That means taking out the historical agitators (hags) also sent back in time in order to keep those events from happening.
As Zed carries out his gruesome but necessary missions, Mullen draws in other characters, spinning a complicated web of betrayals, relationships and pursuits: we meet former CIA operative Leo Hastings, corporate lawyer Tasha Wilson (grieving over the loss of her soldier brother), and a young Indonesian maid being mistreated by her Korean diplomat employers. Mysterious men in dark SUVs from various intelligence agencies crop up at various points.
Complex, dark, and thought-provoking. Sometimes a bit hard to follow, but overall, quite well done. And the cover design is one of the best I've seen in a very long time.