"Here's a little mental virus for you: "For reasons that are obscure to me, but not unimaginable, some of my friends call it 'Duck Machine' instead of 'Deus ex Machina'. Among these friends we call it Harry Potter and the Duck Machine, a delightful image. We used to laugh that Star Trek endings so often employed the Duck Machine, that we imagined this ending written into the script for Star Trek episodes: