He took up a firing stance, holding the thirty-eight out in front of him. "Mr Lennon?" he said. * 1968: Cristian Alvarez meets the Seventh Doctor in London. * 1978: The great temple of the Aztecs is discovered in Mexico. * 1980: John Lennon is murdered in New York. * 1994: A gunman runs amok in Mexico City. The Doctor, Ace and Bernice travel to the Aztec Empire in 1487, to London in the Swinging Sixties, and to the sinking of the Titanic as they attempt to rectify the temporal faults -- and survive the attacks of the living god Huitzilin.