|Wee Free Men|
A new Terry Pratchett novel, or at least new to me, tee hee...
Tiffany read the sign and smiled.
"Aha," she said. There was nothing to knock on, so she added "Knock, knock" in a louder voice.
A woman's voice from within said: "Who's there?"
"Tiffany," said Tiffany.
"Tiffany who?" said the voice.
"Tiffany who isn't trying to make a joke."