Red Doors was originally a fictional terrorist organisation invented by the Sorvix as a scapegoat for 3Sol's actions, including the bombing of the Severn Bridge. (AUDIO: Aliens & Sex & Chips & Gravy) However, it became a real thing with racists such as Xander Vaughn forming a true Red Doors with the goal of getting rid of the Sorvix and minorities from Cardiff. (AUDIO: Poker Face)
As part of their attempts to keep the Sorvix from gaining power, Red Doors killed Detective Inspector Pete Bunton and Professor Helen White, both of whom were tools in Ro-Jedda's plan to outsource policing to 3Sol. Xander found Jack Harkness to get help from him and told him about Red Doors' activities. (AUDIO: The Empty Hand)
Yvonne Hartman successfully used Jack's interactions with Red Doors to convince the Torchwood team that he betrayed them, allowing her to take charge. (AUDIO: Poker Face) He did so. St John Colchester accused him of supplying Red Doors with psychic worms that they then unleashed on the people of Cardiff. (AUDIO: Tagged)
Jack became the leader of the group. Red Doors mainly targeted empty offices and Sorvix targets. Jack attempted to stop them from bombing Cardiff Airport - targeting migrant flights - but was unsuccessful. The passengers of a cheap flight to Alicante were killed rather than the intended targets.
The attack led to Yvonne and Ro-Jedda joining forces to wipe out Red Doors, with Yvonne and 3Sol raiding and arresting them. Jack decided to sell them out to Inspector Bernstein but found that they had already been rounded up. Those who had not been blew up City Hall. (AUDIO: Herald of the Dawn)