And now for the second "The Man Who..." title nominated for a Nebula this year, The Man Who Ended History, by Ken Liu. But jokes seem a bit out of place here, for the story is serious as a heart attack. The driver is an expose of the Japanese Army's infamous Unit 731, which committed many atrocities in WWII in China. The SF portion is a method of time travel that does not interact with the past--interception of the "Bohm-Kirino" particles emanating from a past event. In this way it echoes Pat Forde's In Spirit, which I recently reviewed. The protagonists of the story, a historian and his physicist wife (Kirino) work to preserve the memory of these events against deniers. The story is written in documentary form as a discussion of history, and in that way it's extremely interesting. The protagonists' decision to rely on human memory as the documentation is given thorough examining. In the story, the revival efforts serve to "turn history into religion" by forcing one to decide whether one believes eyewitnesses. In the story the point is made that we distrust eyewitnesses these days.
And surely we do, for good reason. Research done during the first decade of this century indicates clearly that memories are rewritten by the act of remembering them, and in the process changed. A person's recollection of events tells us more about what the person believes than what happened, even for what appears to be merely factual information. Read that linked article for a glimpse of why our children's world will be unutterably strange to us.
As for Unit 731 itself, the story seems to indicate that the deniers are winning even today. It doesn't seem so from my brief research--there's a lot of well-documented work exposing it in detail. The story claims no one was tried for war crimes--Macarthur let them off to keep their work from the Russians. But the Wikipedia article above says at least some of the doctors were tried, and that the Russians did in fact get hold of the research.
As you can see, a very thought provoking tale. Might not be my favorite, but I think it's a pretty strong contender and wouldn't be surprised if if won. I give it 3 stars, but recommend reading it.