You know Ian is a bad ass. No seriously I thought Marco Polo was a adventuring bad ass but Ian has won the heavyweight championship. The Aztec warrior gets his ass kicked more times than a UFC fight by Ian more than once. Barbara tries to change history too. From this we learn of how the Doctor knows there are certain events in history that are fixed in time and can not be changed.
But aside from that the best thing about this episode is when the old woman falls in love with the Doctor. This really got me laughing considering how in later regenerations all women fall in love with this man. I didn't think it would be happening this soon in the series. Damn I wish I had that skill.
For more info on this episode visit my friends at: http://en.wikipedia.org/wiki/The_Aztecs_(Doctor_Who)