Bertram (The Lamentation Cipher)

"Bertram" was the name that Charlotte Pollard gave to a Viyran otherwise known as the Rogue Viyran.

The Lamentation Cipher
Bertram spoke differently to the other members of his species and was light on his feet. He told Charlotte Pollard that the Viyrans didn't know much about the Ever-and-Ever Prolixity. He knew of the Lamentation Cipher. (AUDIO: The Lamentation Cipher)

He infected Charley with a virus that would reboot the Viyrans. He allowed her to escape so it would incubate in her and make it more virulent. (AUDIO: The Viyran Solution)

The Identical Men
The Rogue Viyran dispersed Charley and Robert's pod in order to cushion their arrival and ensure their survival. His own molecules were also dispersed, but he managed to recombine himself at Department 001 and rejoined Charley and Robert, telling them that the Identical Men that confronted them were too dangerous to take on. (AUDIO: Embankment Station) He used his ruffling power on them, causing him to exhaust himself.

Charley and Robert carried the Rogue Viyran to safety and named him "Bertram", a name that he accepted. He told the humans that he believed that the Prolixity had brought them to this time and place due to the presence of something analogous to a virus being present, the Prolixity having latched onto his own purpose for being. They were later taken into police custody and transported to Woking, who unwittingly invigorated Bertram with an MRI and held them at gunpoint when they tried to flee. (AUDIO: Ruffling)

Bertram carried Woking to safety after he collapsed and impeded the Identical Men that came for them by absorbing the electricity in the London Underground's rail. He identified the Identical Men's pulse as some sort of coded message, one which did not affect him nor Charley and Robert, and told his friends that he believed he could feel the Prolixity inside him and that this had given him his ruffling power. When they returned to Embankment tube station and fled from the Identical Men, Bertram was able to make himself, Charley, Robert and Woking disappear. (AUDIO: Seed of Chaos)