Lok

Governor Lok was the robotic governor of Volag-Noc prison until Gurney used a hacking system to take over the jail. He locked up Lok. The Doctor and Martha Jones came to the prison, with the Doctor freeing Lok and Lok rebelling against Gurney. Lok decides that all prisoners must be killed, but he is stopped by the Doctor, and Lok seemingly dies. (DW: The Infinite Quest)

It is not clear whether Lok died, or deactivated.