The series is set in ancient Mexico, when the peaceful god Quala is being usurped by the new and vengeful god, Teshkata; a power struggle ensues between the just Emperor Kukhulkhan (Tony Steedman) and the scheming High Priest Nasca (Troughton). With the new temple built and riddled with secret passageways, Nasca plots his ascension through betrayal, cunning and murder. With the arrival of the rival Toltec army, led by Prince Houtek (Brian Deacon), the Emperor sees a chance for peace by arranging a marriage to his daughter, Chimalma (Diane Keen). This creates tension with the rival suitor Mahoutek, General of the Jaguar Guards (Robert Gray), whose jealousy becomes a tool which Nasca exploits to his deadly advantage. It takes the courage of Houtek's messenger boy, Tozo (Richard Willis) and his blind mentor, the prophetic Otolmi (George Cormack), to find a way to defeat the powers of darkness.
The first series focuses on Nasca's play for power, which leads to the Emperor's murder, the shaming of Mahoutek, the slaughter of the Toltecs and the imprisonment of Houtek. But at the time of the eclipse, the tables are turned on Nasca as he meets his fateful end. Or does he?
The second series follows on directly with Chimalma now preparing her reign with a new ally in court, Mataque (Robert Russell). Meanwhile, Houtek undertakes a series of tests of courage, wisdom and ingenuity to prove that he would make a worthy husband. But Nasca's followers are plotting, and Xipec, Governor of the Gold Region (Granville Saxton), uses the magic of witchwoman, Keelag (Shelia Burrell), to bring the High Priest back to life.
This show provides the following tropes:
- A God Am I: in the finale, Nasca goes from worshipping Teshkata to believing himself to be him.
- Back from the Dead: Nasca in the second series.
- Big Bad: Nasca.
- Big Good: Emperor Kukhulkhan. In the second series, his daughter Chimalma takes his place.
- Cold-Blooded Torture: Xipec has Tozo tortured for information.
- The Dragon: Nasca has two of them; Chadac in series one and Xipec in series two.
- Human Sacrifice: What do you expect, given the setting?