Mr Colchester helped to investigate the Sorvix activities and ensure stability in Cardiff while it was under the Sorvix rule and suffered from constant terrorist attacks. (AUDIO: Aliens & Sex & Chips & Gravy, Orr, Superiority Complex)
After Yvonne Hartman showed up at the Hub and announced that she will depose Harkness and become the new leader of Torchwood, he grew to like her. He then used footage from surveillance cameras and found out that Jack secretly worked with the Red Doors, and was the first to suggest they release Yvonne from the cells. (AUDIO: Poker Face)
While working with Yvonne he started to disapprove of her cruel choices, albeit "for the glory of Torchwood", (AUDIO: Tagged) especially after she sent him and Gwen to investigate an escape room, which nearly killed them and their husbands, (AUDIO: Escape Room) and later showed no sign of compassion whatsoever. (AUDIO: Herald of the Dawn) He also started to suspect that something was off about Gwen. (AUDIO: Escape Room, Herald of the Dawn)
Mr Colchester tried to contain the Rift when it suddenly became unstable. He was shot by the Sorvix assassin sent to kill Tyler Steele, and was present at the Hub when Jack realised that Gwen was not who she seemed to be, and a burst of energy from the Rift separated her from the alien that occupied her body for several months. Tyler and Orr then tried to take the wounded Colchester to the hospital while the Sorvix's god came through the Rift, but he stopped breathing. (AUDIO: Herald of the Dawn)
Behind the scenes
- His first name is pronounced /ˈsɪnʒən/.
- James Goss and Scott Handcock revealed that the character was pitched by Russell T Davies, who helped to develop Aliens Among Us for Big Finish Productions. His idea was to bring an older gay character in a stable relationship, the opposite of Tyler Steele in terms of personality and uncommon in science fiction. (BFX: Aliens Among Us 3)
- Mr Colchester was intended to be Scottish, but when Scott Handcock suggested casting Paul Clayton, he and James Goss decided that he was perfect for the role. (BFX: Aliens Among Us 3)
- The first name of Mr Colchester remained a mystery for quite some time. (VOR 104) It was first revealed in A Kill to a View, the 6th episode of Aliens Among Us. There "St John" was used as a safe word between Mr Colchester and his husband Colin to get out from a dinner party, but Colin also called his husband St John at the end of the episode. The name was later unambiguously stated again in the 9th episode, Poker Face.