Altos

Altos was a young man sent by Arbitan to find the keys to the Conscience of Marinus. Instead he and his friend Eprim were enslaved in Morphoton. 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. Nevertheless Ian did not trust him because his eyes never blinked during the conversation.

After being freed, Altos accompanied the First Doctor and his companions in their search for the keys. He met Varos who tied him up in the forest and abandoned Sabetha and Susan]] in a cave.

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)