Novella, on the shortlist for this year's Hugo. Basically a reimagining of Asimov's End of Eternity, except with a much larger timescale and depiction of the psychical control involved. The starting lines imagine an timetraveling organization acausal and reuthless enough to force recruits to murder their grandparent and wipe out their own personal timeline, then to go on serving them, and rolls from there. Huge amount of intrigue and big ideas tossed off here.
Certainly it’s not short in the department of striking ideas, but the characterization is quite flat, which is problematic given how much of the story hangs on the emotions and actions of the protagonist. I also felt the politics were a bit flat and rather unconvincing in some major ways, and there were elements of the grotesque put in without enough thought on the issue (for instance the whole literalization of the grandfather pardox discussed above.) Actually going with this as a policy makes a lot of the group too unwieldy to be really believed. Plus there's a lot of what I criticized above--a science fiction work interesting in reforming earlier works and winking to fandom instead of honestly exploring its main scenario.
Pretty sure this one won't get my vote for the Hugo, despite some interesting elements in construction.
Worse than: The End of Eternity by Issac Asimov
Better than: The Revolution Business by Charles Stross