He panics the first time he realizes he's forgotten exactly what his elder sister looks like. His brain has been frelled with by half the people living in this universe and a good portion of those outside it - to someone as prone to loopiness as he is, minor memory loss should be the last of his worries.

But as he tries again and again to picture Susan's face, and it slips away and morphs into a thousand others (none quite correct), he panics - because his memories are all that he has left of home in these Godforsaken Territories, and they are slipping away.