Obviously loss of family is huge and critical, but I think really it's more about losing a sense of family. The horror of that kind of incompleteness. Writing this book, I tried not to think about my father, which does no one any good fictionally. I did try to imagine not just the horror of that moment, but the horror of having witnessed it, and the lifelong void. And I think that's what's so frightening.

I want the flashbacks to feel that once you're there they have their own unity, their own kind of atmospheric sensibility; I want the reader to be transported. The novel is a big, complicated, unknowable thing before it's written.

It's not that I wrote those details, but photos can give you the confidence that you have a real feel for the landscape. Then you can invent with a solid kind of faith, and recreate a feel and flavor of the time, and, one hopes, a tonality, a sense of that time having been lived by those characters.

I did a lot of reading of first person accounts from Koreans and combatants and aid workers. And I spoke to relatives. A lot of wonderful photographs were made available to me from that period - 1950-1956 - and those were given to me by a Korean newspaper in Seoul. Ruined villages, refugees streaming through a river valley, GI's and orphans and orphanages, those tiny details that you can only see in a picture.

Obviously loss of family is huge and critical, but I think really it's more about losing a sense of family. The horror of that kind of incompleteness. Writing this book, I tried not to think about my father, which does no one any good fictionally. I did try to imagine not just the horror of that moment, but the horror of having witnessed it, and the lifelong void. And I think that's what's so frightening.

Imagination might not be limitless. It's still tethered to the universe of what we know.

I wanted to write about the Korean War, but I had no entry into it that made the kind of sense it needs to make for a novelist.