Mariah Six

 was a sister unit to Mark Seven. She was the deputy commander of the ALARC and told the Tenth Doctor and Anya Kingdom about the facility. She was curious about the Doctor and Anya and wanted to learn from them. She turned on the recall signal to get Mark back in order to help her escape because she was envious of his travels. She showed him why he was able to leave the premises and how she was involved causing his memory would be wiped. She hoped to have already escaped and that her and Mark's brains could have tricked the system to let them escape, but Mark informed on her. She programmed the recall signal to get Mark back with humans to allow her freedom. Mark pushed her through the door wiping her memory. (AUDIO: Cycle of Destruction)