An Aztec captain guarded the place where Ian Chesterton and Susan Foreman were held for punishment. Cameca used Autloc's seal — an item that signified the right to all his wealth — to distract the guard.
Ian then knocked the guard off and stole his elaborate headdress, so that he could move about the Aztec city with greater ease. The captain was killed by Ixta for his failure. (TV: The Aztecs)