Knock On Wood

Transcript
(Brian is talking to Mac Guy)

Brian: Things are going pretty well for you these days, Mac Guy.

Mac Guy: Quick, knock three times on wood.

Brian: Why?

Mac Guy: Because if you say how well things are going and you don't knock on wood, you're inviting bad luck!

Brian: You don't really believe that, do you?

Mac Guy: You bet I do! Now hurry up and find wood to knock on before...

(Suddenly, a huge piano falls from the sky and lands on Mac Guy. Brian looks at the piano and knocks on it)