Altos (The Keys of Marinus)

Altos was a young dark haired man sent by Arbitan to find the keys to the Conscience of Marinus. Instead he and his friend Eprim were enslaved in Morphoton thanks to power of the Mesmeron.

As a Morphos' slave he welcomed Barbara in the city, offering her to grant every wish of her. He did the same with Susan and The Doctor, who respectively asked for a fancy dress and a complete visit to the laboratories. He assented to both their requests. Nevertheless Ian did not trust him because his eyes never blinked during the conversation. When Barbara proved herself resistant to the power of the Mesmeron, the Morphos ordered him to kill her. So when he found her he tried to strangle her but he was hit over his head with a stool by Sabetha and then collapsed.

After being freed, Altos accompanied the First Doctor and his companions in their search for the keys in the city of Millennius, showing the Doctor how to adjust his travel dial. Unfortunately, he later met Varos who tied him up in the forest, in the company of the wolves, and abandoned Sabetha and Susan in a cave. He was then freed by Ian and helped him in saving Barbara from Varos, who was trying to rape her, and in rescuing Sabetha and Susan in the cave protected by the Ice Soldiers.

He and Sabetha were romantically involved, which was exploited by the Voord, Yartek, who forced him to hand over one of the Conscience's keys. (DW: The Keys of Marinus)