Another one of my jokes (4)

Only have time for a joke for today's post; this one was written for Christmas 2009:

"In the final Harry Potter book, why was Potter looking for Avon? He was searching for the Deathly Darrows."

This is one of my more obscure-humoured jokes: to understand it, you not only have to have read Harry Potter and the Deathly Hallows, but you also have to have watched a 1970s television show entitled Blake's 7. In that show, there was a character called "Avon", and he was played by the actor Paul Darrow. I have rarely used this joke outside Christmas 2009 because of its obscurity, but I think it is a good one nonetheless...it just needs to be told in the right circumstances.