Ace

Ace, real name Dorothy (Dorothée) Gale McShane, was a companion of the Seventh Doctor. She was a human from late 20th century Earth. A native of the London suburb of Perivale, she was born on 20th August 1970. (NA: Timewyrm: Revelation, Falls the Shadow, Set Piece, PDA: Relative Dementias)

Biography
In her youth, Ace had been a troubled teen on Earth, having been expelled from school for blowing up the art room as a "creative statement". Gifted in chemistry (despite failing it for her "O"-levels), she was in her room experimenting with the extraction of nitroglycerin from gelignite when a time storm swept her up and transported her to the deck of Sabalom Glitz's spacecraft docked at Iceworld far in her future. (NA: Love and War) Trapped on Iceworld, she got a job as a waitress and (an unknown time later) met the Doctor and his companion Mel. When Mel left the Doctor at the conclusion of their battle with Kane, he offered to take Ace with him in the TARDIS, and she happily accepted. (DW: Dragonfire)

Ace had suffered several traumatic events in her childhood, including a bad relationship with her mother and the racist firebombing of her friend Manisha's flat. (Manisha died in the fire-bombing, and Ace in anger set fire to Gabriel Chase, a long abandoned mansion rumoured to be haunted by an ancient evil (DW: Ghost Light, NA: Blood Heat)). Consequently, Ace covered up her own fears and insecurities with a streetwise, tough exterior. Her weapon of choice, disapproved of by the Doctor (who nonetheless found it useful on occasion), was a powerful explosive she called "Nitro-9", which she mixed up in canisters and carried around in her backpack.

Affectionately giving the Doctor the nickname of "Professor", she was convinced that the Doctor needed her to watch his back, and protected him with a fierce loyalty. In turn, the Doctor seemed to take a special interest in Ace's education, taking her across the universe and often prompting her to figure out explanations for herself rather than giving her all the answers.

Early travels
Under the Doctor's tutelage, Ace fought the Daleks and faced Davros in 1963. (DW: Remembrance of the Daleks). She later faced Helen A and her sadistic government, which required people to be happy on pain of death. (DW: The Happiness Patrol) She stopped the Cybermen from getting hold of Nemesis in 1988 (DW: Silver Nemesis), and saved the Psychic Circus on Segonax from the Gods of Ragnarok. (DW: The Greatest Show in the Galaxy) She also met the Brigadier Lethbridge-Stewart and helped UNIT defeat the Destroyer and Morgaine. (DW: Battlefield)

The Doctor did make Ace face demons from her past including taking her to a house she burned down 100 years before burning it down. There was an Entity in the house known as Light, and Ace had felt his presence in the house, so she burned it. (DW: Ghost Light)

Ace's arrival on Iceworld was not accidental, but in fact part of a larger scheme conceived by Fenric. Ace was a "Wolf of Fenric", one of many descendants of a Viking tainted with Fenric's genetic instructions to help free it from its ancient prison, and a pawn in the complex game between it and the Doctor. The Doctor appeared to have been aware of this from their first meeting, although Ace was not. After Fenric was defeated, Ace continued to journey with the Doctor. (DW: The Curse of Fenric)

Ace did return to Perivale where she found that all her old friends had gone missing. She thought that they had moved on, but in fact they had been taken to the Cheetah World as prey for the Cheetah People. She found the Master, an old enemy of the Doctor, was using them so he could get off the Planet. Ace returned with two of her friends and she went of to travel with the Doctor again. (DW: Survival)

Further journeys with the Doctor
Sometime after encountering the Master in Perivale, she encountered the Master's influences involving Duchamp 331 and encountered for the second time Bev Tarrant. (BFA: Dust Breeding).

Following an encounter with Nazis, the Doctor took Ace to Ibiza in 1997 to 'relax' following her ordeal (BFA: Colditz). Whilst in Ibiza she discovered that she had a brother; Liam McShane. (BFA: The Rapture)

Journeys with Hex and the Doctor
Whilst in London in 2021 investigating with the Doctor evidence of 'xenotech' use—use of alien technology on humans—in fact Cyber technology, she met Hex, a nurse working at St Gart's Hospital; following his help she convinced him to join her and the Doctor, taking him under her wing somewhat. (BFA: The Harvest)

Later travels with the Doctor and Bernice Summerfield
Indications exist that the Doctor had plans to eventually take Ace to his homeworld of Gallifrey and secure her admission to the Prydon Academy, possibly as part of his assumed mission as "Time's Champion". However, Ace became more and more frustrated with the Doctor's manipulations, eventually leaving his company (NA: Love and War) at age 26 (NA: Set Piece). She joined Spacefleet and fought the Daleks for three years, later rejoining the Doctor and Bernice Summerfield, older and more hardened (NA: Deceit). Ace's relationship with Bernice was at first less than cordial, possibly out of jealousy, but the two eventually became friends.

Ace's relationship with the Doctor remained strained for some time, but they eventually resolved their differences. Finally, after their ordeal with the Ants, Ace left the Doctor again to become Time's Vigilante, using a short-range time hopper mounted on a motorcycle to patrol a particular segment of time; in effect doing what the Doctor does, but on a smaller scale. (NA: Set Piece)

Life after the Doctor
Sarah Jane Smith found during a search for previous companions of the Doctor on Google that a "Dorothy something" was alive and well and running a company called A Charitable Earth - the initials of which spell "ACE". (SJA: Death of the Doctor)

Alternate fates
Varying and contradictory reports of Ace's eventual fate exist. She may have been killed by the Threshold sometime before the Seventh Doctor's regeneration into the Eighth Doctor. (DWM: Ground Zero) One report even claims she inherited the mantle of the Time Lords when they became extinct. (WC: Death Comes to Time) Yet another account suggests that she eventually comes to live in Paris in 1887 after leaving the Doctor. (DWN: The Curse of Fenric, NA: Set Piece)

Other possibilities
Quite possibly this confusion is owing to the existence of an alternate reality containing a young woman, also called Ace, who traveled through time in the company of a mystery figure known as "The Professor". Yet another reality is known to exist whose version of Ace, called "Alice", accompanies a time traveller known as "The Dominie". A human matching Ace's description and personality (and heard making references to a "Professor") was also reportedly involved in a series of competitions involving a Sontaran and a Draconian. (RP: Mindgame)

Behind the scenes

 * Ace's full name was never revealed on the television series, in which she was usually referred to by her nickname, Ace. Her surname was not established until original novels featuring the character were published, however her name Dorothy was referred to on screen in DW: Dragonfire and (possibly) in SJA: Death of the Doctor.
 * Ace was the final female television companion to date not to kiss, or be kissed by, the Doctor until Adelaide Brooke in 2009.
 * Though novels and comic strips had put forward scenerios regarding how Ace finally departs the Doctor's company, the TV series itself did not. She was the only companion to date whose fate (or at least her departure from the TARDIS) had not been revealed on screen. Her final fate was still not revealed on the show itself. Rather, in SJA: Death of the Doctor, a reference was made to a former companion of the Doctor named "Dorothy" (presumably, though not certainly, Ace) who was running an organisation known as "A Charitable Earth".