Worlds of Ultima: The Savage Empire/Nahuatla tribe

Nahuatla tribe
The rightful king of the Nahuatla is an exile in the Disquiqui village. Still, talk to all the people in Tichticatl (the city of the Nahuatla) and learn as much as possible. DON'T talk to the guards!

Note that "Zipactriotl" is just an alternate spelling of "Spector", with modified phonetics, as shown below: S--PEC-T---OR Z--PEC-TR--OL ZI-PAC-TRI-OTL

Item list
A full list of items can be read in the Yolaru tribe#Apaton's trial page.

Right now, the only important thing is to retrieve the gold head from the palace. It is found in the treasure room, specifically the center-north behind the throne room's wall.

Moctapotl's trial
Moctapotl is exile in the Disquiqui village. He asks you to restore him to his throne, and only then he will join the alliance of the tribes. He hints at the fact that Oaxtepac knows something about the origin of the powers of Zipactriotl and Huitlapacti.

The shaman Oaxtepac is in the prison, in the west of Tichticatl. Talk to him until he says something about the mighty beings and their city. You will need two items to access the Kotl city: the giant gem and a golden head; Oaxtepac knows where to find them.

The queen Tlapatla gives you the real reason to visit the Kotl city: she learned that the power of Spector and Huitlapacti has its source in there. She can be met in the Nahuatla palace.

Furthermore, another character who speaks about the Kotl ruins is Cleese, the parrot in the Nahuatla palace. He actually links Spector to Fritz, who lives near the Pindiro village. Fritz can give you the crystal brain, that will be useful in the Kotl city.

One last character who speaks about the Kotl ruins is in the Sakkhra tribe. Sysskarr, the Sakkhra chieftain, expands what Oaxtepac said about finding the Kotl city from the mesa top.

Next destination
Once you collected the giant gem, the gold head and the crystal brain, let's get into the Kotl ruins.