As I was reading about Cope and Marsh, I ran across Knight as something of a bit player in their lives. As I got further into the Cope and Marsh story, and I liked the two less and less as people—which is different from liking them as characters, of course—I wanted to have a character in the book for the readers to root for, and neither of the scientists could fill that role. When I found out that Knight had met Cope just before Cope died, I became convinced that he was the character I needed.