'The Aztecs' and 'The Keys of Marinus' often vie for the title of 'Favorite Season One Story,' as they're both brilliant, but in quite different ways. Here we're treated to yet another impressive opening episode, with Hartnell still apparently riding that post-vacation energy boost. The way he delivers that iconic speech sends shivers. The Doctor and Barbara play off each other perfectly throughout this story; Susan bounces between playful, horrified, and outraged; and Ian is often forced to stand by and watch others wield the agency he so often does. The supporting cast is wonderful, too, imbuing their characters with just the right amount of pathos to help convey the sense of darkness and inevitability that pervades this story. And make no mistake - the story is quite dark. Our heroes seemingly cannot catch a break as they, and the Aztecs they've met, maneuver for position about the board (Tlotoxl is delightfully slimy and off-putting), with the resolutions of their various gambits yet to come. Indeed, our main characters back themselves into corners by being too clever by half (including a lovely subplot involving The Doctor's engagement). But how can they do otherwise than hold to their various convictions? The character development really shines through in this story, and there is just so much to love here - this TARDIS team has really come together, resulting in another easy 10/10 from me.