Ah, Utopia. This Series 3 classic will go down in history for its climactic cliffhanger which heralded the 21st century, and long overdue return, of the Doctor's arch nemesis. Yes, another one! When viewers were introduced to Derek Jacobi as Professor Yana at the end of the universe, they had no reason to suspect that he would turn out to be such an important figure within the Doctor Who mythology, let alone that he would single-handedly fulfil the Face of Boe's prophecy to the Doctor that foretold him, "You are not alone". The clue was in the Professor's name, really. A veteran of the stage and screen, Jacobi's stint on screen was destined to be short lived, however, when it eventually transpired that he was actually the Master in a human disguise. You didn't see that one coming now, did you? OK. You probably did. In one of the most heart-stopping cliffhangers of all time (chan - seriously - tho... this one was all kinds of epic!), this incarnation of the Master was promptly shot dead by his female companion which is pretty much the story of his life. He proceeded to regenerate into John Simm before stealing the Doctor's TARDIS which put our heroes in a rather sticky situation to say the very least. Nobody saw the comeback of this renegade Time Lord coming but let's all be thankful that it did. End of the universe, have fun! Bye bye! And there was plenty more where that came from, too...