Hogfather - Occult Sequence

“Yes! Yes! Left-handed using a wooden pick! That’s simple!”

He saw that even Susan was looking at him, and coughed nervously.

“Er, I’ve got the fifth lock open, Mister Teatime! Not a problem! They’re just based on Woddeley’s Occult Sequence! Any fool could do it if they knew that!”

“I know it,” said Teatime, without taking his eyes off Susan.

“Ah…”

It was not technically audible, but nevertheless Susan could almost hear the wizard’s mind back-pedaling. Up ahead was the conclusion that Teatime had no time for people he didn’t need.

***

Hogfather - p305