One Rule (audio story)

 was the fourth story in the Torchwood audio series by Big Finish Productions. It was written by Joseph Lidster and featured Tracy-Ann Oberman as Yvonne Hartman.

It featured Yvonne Hartman for the first time in any medium since her television debut.

Publisher's summary
It's been three weeks since the Mayor of Cardiff was killed by a shop dummy and the fight is on to see who will replace him.

Yvonne Hartman is visiting the city to retrieve an invaluable alien device. She's in charge of Torchwood One, she's saving the British Empire and she doesn't care about local politics. But she is going to find herself caught up in that fight. There's a bloodthirsty alien stalking the streets and there's a special offer on at the all-you-can-eat Chinese buffet.

It's the 26th of March 2005 and it's the day that everything changes.

Plot
to be added

Cast

 * Yvonne Hartman - Tracy-Ann Oberman
 * Barry Jackson - Gareth Armstrong
 * Helen Evans - Rebecca Lacey
 * Ross Bevan - Dan Starkey
 * Meredith Bevan - Catrin Stewart

Uncredited cast

 * Gwen Cooper - Eve Myles
 * Andy Davidson - Tom Price

Continuity

 * Whilst talking to Ianto on the phone, Yvonne tells him to ask Lisa Hallett out. (TV: Cyberwoman)
 * Torchwood One are attempting to ascertain the nature and purpose of the Void Ship. (TV: Army of Ghosts / Doomsday)
 * Torchwood Three possesses a Drahvin scanner, which is procured by Yvonne. (TV: Galaxy 4)
 * Yvonne says "Happy Day". (TV: Army of Ghosts)
 * The Lord Mayor of Cardiff Roy Llewellyn was killed by the Auton invasion which reached Cardiff on 5 March 2005. (TV: Rose) He would eventually be succeeded by Blon Fel-Fotch Passameer-Day Slitheen, posing as Margaret Blaine. (TV: Boom Town)
 * Both Barry and Helen, who are running in the mayoral race, moan about London's lack of interest in Cardiff. This is reminiscent of when Blon went "native" during her time as Lord Mayor. (TV: Boom Town)
 * A cover story was concocted to explain away the invasion on 5 March as a "terrorist attack". Such measures were previously taken for the first Auton invasion in the 1970s. (PROSE: Who Killed Kennedy; TV: Spearhead from Space)
 * Yvonne speaks of the incident on New Year's Eve 1999 involving the murder of the Torchwood Three team by its leader Alex Hopkins, who went mad after seeing the coming "change" in the 21st century before committing suicide. (TV: Fragments)
 * Yvonne says that she is doing it "for Queen and Country" before downing a pint of Diamond White beer. She would maintain that she did her duty for Queen and Country immediately before her forced cyber-conversion during the Battle of Canary Wharf in 2007. (TV: Doomsday)
 * Gwen Cooper and Andy Davidson are members of the Cardiff police force. (TV: Everything Changes)
 * Yvonne says, "When I say 'run'..." (TV: The Tomb of the Cybermen, et. al)
 * Yvonne tells Barry and Helen that she is a people person. (TV: Army of Ghosts)
 * Skip Jameson was still working at the Priory Nightclub in 2009. (AUDIO: In the Shadows)
 * Yvonne explains to Helen and Barry that Torchwood's presence in Cardiff is down to the space-time rift running through the city. (TV: The Unquiet Dead, Everything Changes) Yvonne states that alien objects and species come through the rift and that Torchwood seizes them and uses them to defend Britain. (TV: Army of Ghosts)
 * Helen was born and raised in Splott. (TV: Ghost Machine, Random Shoes, et. al)
 * Ianto manages to hack into a London Credit Bank ATM. (TV: The Runaway Bride)
 * Barry is an enabler of the Committee. (AUDIO: The Conspiracy)
 * Yvonne says, "If it's alien, it's ours". (TV: Army of Ghosts)
 * Yvonne tells Barry that Torchwood is awaiting the return of one particular alien to Cardiff. (TV: Boom Town)