A handwritten notebook by Alan Turing is going on the auction block. The Nazi code-breaking genius is depicted by Benedict Cumberbatch in the Oscar-nominated The Imitation Game. It’s expected to sell for at least $1 million at Bonhams in New York on April 13. The 56-page manuscript was written when the mathematician was working to break the German Enigma codes used throughout World War II. The auctioneer says it’s believed to be the only extensive Turing manuscript known to exist.