Everybody loves a crafty hero. And nothing says "crafty" better than pretending to swap sides. No matter how many times a good guy pretends to betray his/her friends, they always act shocked. But what's the absolute best "pretending to go over to the enemy" scenes?
Please include a picture or clip of this shocking "betrayal." And please mention the name of the hero, the TV show, comic, movie or book, and why it was such a clever ploy.
Top image: My personal favorite is Doctor Who, "Claws of Axos," where the Doctor pretends to join the Master. The Doctor is so desperate to escape from Earth, it seems actually plausible that he might go through with it.