John le Carré's acclaimed 1974 novel about George Smiley, a spy tasked with uncovering the mole at the top of British Intelligence, was first made into a popular BBC miniseries starring Alec Guiness as Smiley in 1979. Now, in an update, Gary Oldman is taking on the role of Smiley, with actors including Colin Firth and Ciarán Hinds as possible suspects.