There are many different parallel worlds that exist beyond our one. Between each parallel universe is a space of nothing called the Void. Travelling between dimensions is scientifically impossible. Nevertheless, the Doctor and his companions have visited parallel universes many times throughout Doctor Who‘s history. Often parallel Earths are very different to our own and are sometimes dystopian and scary.

Inferno

★★★★★

TX: 09/05/1970 – 20/06/1970

Written by Don Houghton    Directed by Douglas Camfield

A mo-hole drilling project headed by Professor Stahlman is trying to reach the Earth’s core. However, the Third Doctor warns that this will unleash geological forces that will destroy the Earth. U.N.I.T are providing security for the scientific project and they find that a member of Stahlman’s staff has become a werewolf-like Primord after touching a green substance in the facility. The Doctor steals energy from the complex in order to restart his TARDIS console. However, this accidentally throws the Doctor into a parallel universe where Britain is a fascist state and the Doctor’s friends (Brigadier Lethbridge-Stewart, Liz Shaw and Sergeant Benton) are all essentially Nazis. The Doctor escapes capture multiple times. However, the mo-hole drilling project is at a more advanced stage than in our universe. Many staff on the project, including the parallel Stahlman and Benton, have turned into terrifying Primords. The drilling project breaks through the Earth’s crust leading to the eventual destruction of the parallel world. The Doctor makes it back to the TARDIS console and with help from the parallel Liz is able to escape back to our universe in the nick of time. The Doctor desperately warns Professor Stahlman of the devastating consequences of the drilling project in our universe. Stahlman becomes a Primord and the project is stopped. The Doctor and the Brigadier make amends. Liz Shaw returns to Cambridge shortly after the events of this story. Many of the amazing stunts in Inferno and throughout the Jon Pertwee era were performed by the talented HAVOC stunt team.

Battlefield

★☆☆☆☆

TX: 06/09/1989 – 27/09/1989

Written by Ben Aaronovitch    Directed by Michael Kerrigan

Knights from a parallel universe, where the Legends of King Arthur are real, arrive in our universe. The area surrounding a dig becomes their battleground and U.N.I.T is caught in the crossfire. Brigadier Lethbridge-Stewart is brought out of retirement to assist Brigadier Winifred Bambera in the fight against the knights. The Seventh Doctor is recognised by Knight Ancelyn as Merlin. Ancelyn and the evil Mordred engage in close combat. Mordred’s mother Morgaine wants to unleash the Destroyer upon the world unless the Doctor returns the legendary sword Excalibur to her. Ace discovers Excalibur in Arthur’s ruined spaceship beneath the lake near the dig. The Doctor follows Morgaine through a portal to her castle. Morgaine frees the Destroyer, but Brigadier Lethbridge-Stewart shoots silver bullets into it which defeats it. Back at the convoy, the Doctor confronts Morgaine, telling her of Arthur’s death. Mordred and Morgaine are then imprisoned.

Rise of the Cybermen/The Age of Steel

★★★★☆

TX: 13/05/2006 – 20/05/2006

Written by Tom MacRae    Directed by Graeme Harper

In a parallel world, billionaire businessman John Lumic invents the Cybermen (metal men with human brains welded inside them) as the next evolutionary step for mankind. Lumic’s lucrative Cybus Industries manufactures all technology on the planet, including the EarPods worn by most citizens for the daily download. Lumic’s henchman Mr Crane is kidnapping homeless people and cruelly experimenting on them to turn them into Cybermen. I have seen so much homelessness throughout my life and it saddens me, more should be done to end homelessness! The Tenth Doctor, Rose and Mickey accidentally arrive in the parallel universe, where Rose discovers that her father Pete is still alive and Mickey discovers that his grandmother is still alive too. The parallel world is a “gingerbread house” of ‘what ifs’. The Doctor and Rose infiltrate Pete Tyler’s house staff on the night of his wife Jackie’s birthday. Parallel Jackie Tyler wears a very low cut dress in this story – the bum is important, but for me I am all about the boobs when it comes to women! Jackie Tyler is a MILF! Unfortunately, the party is stormed by a squad of Cybermen who kill everyone in the house. The Doctor, Rose, Pete, Mickey and the Preachers (an anti-Cybus Industries rogue group) escape in a van, whilst Jackie hides in the house’s basement. Lumic activates a signal to bring all of the humans in London under his control by inducing hypnosis via those wearing EarPods. The hypnotised humans (including Jackie) walk towards Battersea Power Station to be converted into Cybermen. Cyber Conversion is a process that involves a human brain being removed and put inside a suit of armour – a painful death for the victim. Whilst escaping from the Cybermen, Mickey’s parallel counterpart Ricky (the leader of the Preachers) is killed, however the Doctor says that he did not die in vain.

The Doctor, Rose, Mickey, Pete and the Preachers infiltrate Battersea Power station at three different points: above, between, below. The Doctor and Mrs Moore make their way through cooling tunnels. However, Mrs Moore is killed by a Cyberman and the Doctor is captured. Rose and Pete make their way through the factory floor with fake EarPods, whilst thousands of unfortunate humans are converted into Cybermen around them. Pete and Rose make the shock discovery that the parallel Jackie has been turned into a Cyberman too and they have arrived too late to save her. Pete and Rose are captured and are brought to Cyber Control along with the Doctor. The Doctor, Rose and Pete meet the Cyber-Controller, Lumic has been unwillingly upgraded after his henchman Mr Crane attacked him. Mickey and Jake gain access to Lumic’s zeppelin on the roof, where they disable the EarPods allowing the surviving humans to escape. Jake and Mickey also cancel the emotional inhibitors of all the Cybermen, causing them to go insane and explode. The Doctor, Rose, Pete, Mickey and Jake escape in Lumic’s zeppelin, narrowly avoiding deletion by the Cyber Controller – which falls to its death in the exploding factory below. Mickey chooses to stay behind on the parallel Earth to continue the fight against the Cybermen, so the Doctor and Rose return to our universe without him.

Army of Ghosts/Doomsday

★★★★★

TX: 01/07/2006 – 08/07/2006

Written by Russell T Davies    Directed by Graeme Harper

The Tenth Doctor and Rose return to present day London to visit Rose’s mum Jackie. However, the world is overrun with ghosts that appear on regular shifts thanks to the Torchwood Institute. The Doctor conducts experiments on a ghost to find its origin. Then he, Rose and Jackie travel to Torchwood’s headquarters in Canary Wharf to find out more. The head of Torchwood, Yvonne Hartman informs the Doctor that the secret Torchwood Institute was established in 1879 by Queen Victoria in order to combat extraterrestrial threats to the British Empire, including the Doctor (Tooth and Claw)! The Doctor discourages Torchwood from conducting further ghost shifts, as this is further fracturing the fabric between dimensions caused by the arrival a gigantic sphere kept in the base. The sphere is a void ship which contains the last surviving Daleks, the Cult of Skaro – a secret order created by the Dalek Emperor. The ghosts turn out to be Cybermen that have followed the void ship and crossed into our universe from the parallel world that the Doctor and Rose previously visited.

The Cybermen have infiltrated Torchwood through the use of their drones, but Rose’s boyfriend Mickey Smith has also crossed over from the parallel world. Mickey and Rose become prisoners of the Daleks. The Daleks need the handprint of a time traveller to open the Genesis Ark, a dimensionally transcendental Time Lord prison ship containing millions of Daleks. The Daleks and the Cybermen wage war against each other and Torchwood becomes their first battleground. During the Battle of Canary Wharf, the Doctor unites with Rose’s parallel father Pete Tyler and Jake Simmonds whilst Jackie narrowly escapes being upgraded into a Cyberman (Yvonne Hartman is less fortunate). The Doctor realises that he, Rose, Mickey, Pete, Jake and all of the Daleks and Cybermen are soaked in background radiation as a result of travelling through the void between dimensions. The Doctor plans to reverse the ghost shift which will suck all of the Cybermen and the Daleks back into the Void. The Doctor tries to convince Rose to join her mother and the rest of her family in the parallel world where she will be safe. But, Rose refuses because she doesn’t want to leave the Doctor’s side. The Doctor and Rose open the breach which sucks all of the Daleks and Cybermen back into the void. Rose is almost accidentally sucked into the void too, but Pete returns and rescues her at the last moment. Rose is trapped in the parallel world with her family, but she manages to say a heartbreaking goodbye to a hologram of the Doctor on Bad Wolf Bay.

Turn Left

★★★★★

TX: 21/06/2008

Written by Russell T Davies    Directed by Graeme Harper

Whilst visiting the Oriental planet of Shan Shen with the Tenth Doctor, Donna Noble meets a fortune teller. The fortune teller tricks her into allowing a Time Beetle (a member of the Trickster’s Brigade) to climb onto her back. The Time Beetle creates a parallel universe around Donna, a world in which she never met the Doctor. In this terrifying alternate reality, the Doctor died during the events of The Runaway Bride, meaning that he was not around to repel all subsequent alien invasions. This leaves the Earth devastated following the spaceship Titanic crashing into London and millions of Americans dissolving into Adipose. Donna, her mother Sylvia and her grandfather Wilf are evacuated along with thousands of other Londoners to Leeds. Donna meets Rose Tyler, a former companion to the Doctor from our universe. Rose tells Donna that she has to go back in time and turn left when she makes the decision to join the job that will ultimately lead her to meeting the Doctor. With help from U.N.I.T and a recovered TARDIS, Rose manages to send Donna back in time. Donna runs out of time and she therefore sacrifices herself to prevent her earlier self from turning right. By turning left, the earlier Donna puts history back on track, bringing an end to the parallel universe around Donna. Donna tells the Doctor that she met Rose Tyler in the parallel world and gives him the vital warning that Rose gave her: Bad Wolf.