Liu has written this story in a documentary style, as if the participants are speaking into a camera, so each anecdote is told in the first person. There are major players, who advance the narrative, and anecdotes from “regular” people, representing the tide of public opinion, that alternate through the story.

Dr. Akemi Kirino and her husband, Dr. Evan Wei, found a way to go back in time, thanks to subatomic particles called Bohm-Kirino particles. They can only go back once, and then no one can go back to that point in time again.

During the Second Sino-Japanese War of World War II, there was an “Asian Auschwitz,” Unit 731 or Pingfang. There, in 1940, scientists tested biological and chemical weapons in the compound, killing between 200,000 and half a million Chinese prisoners. Evan plans to focus his and his wife’s time-travel technique on the atrocity, sending volunteers to bear witness.

The decision is fraught with controversy. One historian, Archibald Ezary says, “What role, if any, we wish to give the voices of the past in the present is up to us” (399), while Chung-Nian Shih of the National Independent University of Taiwan questions Evan’s decision to send volunteers rather than historians or journalists, especially since these moments in history can only be seen once.