This four-parter allows "Barbara" (Jacqueline Hill) a little more of the plot as the time travellers arrive at the height of the Aztec empire. Despite firm instructions from the "Doctor" (William Hartnell) not to wander, she goes for a stroll and is soon apprehended on the wrong side of a stone door by "Autloc" (Keith Pyott) who takes her somewhat miraculous arrival as a sign from their god "Yetaxa". Next thing, she's the High Priestess and she and her colleagues are all having to walk a fine line between the powers that be in the city and those more sceptical of her appointment and who turn things distinctly perilous for poor old "Ian" (William Russell) who ends up at the mercy of the malevolent "Tlotoxl" (John Ringham). He also has it in for "Susan" (Carole Ann Ford) too! This story works quite well mixing a solid base of interesting mythology with some decent writing and plenty of intrigue as the wooden axes become increasingly sharpened! There are no special effects to speak of, so no latex and polystyrene distractions from quite an entertaining and well-paced adventure.