Zet was a humanoid Dalek scientist working in a secret base in the Polar Mountains along with Lodian and Yvric. He was unaware that Lodian and Yvric had discovered the location of the planet Earth, and constructed a spacecraft to go there. When the neutronic war occured, the pole shifted and all three were frozen alive in ice. Centuries later, a Dalek hoverbout accidentally revived them, and they soon determined that they were the last of the original Daleks and that Yarvelling's creations had become the rulers of Skaro. When Yvric was exterminated, Lodian told him about Earth and the spacecraft. However, Zet knocked him out and handed him over to the Daleks, hoping to bargain with them. When Lodian escaped, Zet pursued him back to their base, where he was killed when Lodian destroyed the spacecraft. (TV21: Legacy of Yesteryear)