Her study of the Cipherers' Market, and particularly of the rule-books used 
by the cipherers to respond to messages, had taught her that for all its 
complexity, it too was nothing more than another Turing machine. She had come 
here to the Castle of King
Coyote to see whether the King answered his messages according to Turing-like 
rules. For if he did, then the entire system—the entire 
kingdom—the entire Land Beyond—was nothing more than a vast 
Turing machine. And as she had established when she'd been locked up in the 
dungeon at Castle Turing, communicating with the mysterious Duke by sending 
messages on a chain, a Turing machine, no matter how complex, was not human. It 
had no soul. It could not do what a human did.