These included his accusation of the Fifth Doctor and Amy for trespassing, even though it was actually Zara and Harmonious 14 Zink. As he talked him them, he liked to play guessing games. After Zara had converted a segment of the Key to Time, which was the capstone of a pyramid, and fled the scene, he rescued Zink, the Doctor and Amy from a collapsing gravity well. Isskar saw the atmospheric changes on Mars, and the adaptation of the Martians from peaceful craftsmen into the Ice Warriors.
Decades later, with the help of Zara, Isskar, now an Ice Lord, left Mars in a ship with a group of Ice Warriors to find the Doctor and the Key to Time, putting themselves in suspended animation. They awoke 16,000 years later, finding the Doctor in a Valdigian castle on Safeplace also searching for a segment to the Key to Time, which was the castle itself. He was trapped inside the segment when Zara converted it into crystal form. After being released by Amy, he imprisoned the Doctor on his spacecraft on Zara's orders, confiscating the two segments they had. He helped the Doctor and Amy retrieve their segments as his ship was destroyed by Zara. He escaped in an escape pod before his ship fell into the red giant, Leboon. (AUDIO: The Judgement of Isskar)