Doctor Who

1. Doctor Who (BBC, 1963-89, 2005-Present) It happened around 1979: A villain bent on distorting time and improving his own standing at the expense of humanity has trapped the Doctor (Tom Baker). Erudite bordering on the effeminate, this evil agent regards the smiling, jovial Doctor with a mixture of bemusement and contempt.

"You," he says to the Doctor, "are dangerously clever."

And that's it. That's the sum total of the premise behind "Doctor Who," the British sci-fi series that has proven itself to be the most durable, most charming, most altogether fun excursion into the unknown on the dial to date. The Doctor's superpower is simply that he's an incredibly smart man, a "Time Lord" with an ambiguous past who uses an antiquated police call box (the TARDIS, or Time And Relative Dimension In Space) to surf through the ages like an astrophysicist Laird Hamilton. Armed only with his wits (and a sonic screwdriver), often accompanied by a female companion (the audience's gape-mouthed stand-in), the Doctor plunks himself into impossible circumstances and then finds a way out. Aliens want to vaporize Earth and then sell off the chunks to the highest galactic bidder? He'll deal with it. A villain wants to steal the Mona Lisa so he can sell the six duplicates to unsuspecting art collectors? The Doctor will buzz himself into da Vinci's pad and write "This is a fake" in black magic marker on each of the drafts. Wanna see the literal end of the world, five billion years from now? He's got your first-class ticket.

To call "Who" a science-fiction fable is a bit of a mislabeling: Because of his kinetic, restless whims, he can drop himself (and the viewer) into any genre. Horror. Fantasy. Romance. Current Doctor David Tennant has even expressed interest in adding a musical to the series' 725 installments.

More than 800 years old, the Doctor–we never learn his true name, hence his working title–has the ability to re-generate himself up to twelve times when critically wounded. The '60s played host to Doctors who were older, sophisticated and charged gamely through cardboard sets; the '70s employed Baker, who adorned himself with a free-flowing scarf that rivals the fabric of any Todd McFarlane cape ever drawn; the fabulously deranged resurrection of the series in 2005–after a 16-year hiatus–brought us Doctors Nine and Ten, with Number Eleven (Matt Smith) on call for 2010.

With his regenative lives running out, it's possible "Who" could finally disappear into the black hole of time. If it's truly the end, it will stand as sci-fi TV's most deliriously imaginative creation. But if anyone can figure out the perscription for TV immortality, it's the Doctor. Watch This: "The End of the World," a jolly 2005 introduction to the retooled franchise and Christopher Eccleston's manic interpretation of the Doctor.

Regeneration
Renegeration, in the context of the long-running British science fiction television series Doctor Who, is a biological ability exhibited by the Time Lords, a race of fictional humanoids originating on the planet Gallifrey. This process allows a Time Lord who is old or mortally wounded to undergo a transformation into a new physical form and a somewhat different personality. The process has been used nine times to introduce a new actor for the role of the main character of the programme, the Doctor.

Conceptual history
The role of the Doctor had been played by William Hartnell at the programme's inception in 1963. However, by 1966, it was increasingly apparent that Hartnell's health was deteriorating and he was becoming more difficult to work with. By the time the second story of Season 4, The Tenth Planet, was greenlighted, the decision had been made to replace Hartnell. Script editor Gerry Davis proposed that, since the Doctor had already been established as an alien, the character could die and return in a new body. Producer Innes Lloyd further suggested that the Doctor could do this "renewal" regularly, transforming from an older man to a younger one. This would allow for the convenient recasting of the role when necessary.

At the conclusion of The Tenth Planet, the First Doctor collapses from apparent old age and exhaustion, having commented earlier that his body was "wearing a bit thin". Then, before the eyes of his companions Ben and Polly, and the viewing audience, his features shift into that of the Second Doctor, played by Patrick Troughton.

However, on screen, the process was not called "regeneration", but a "renewal". In The Power of the Daleks, the Second Doctor's first story, the Doctor draws an analogy between the renewal and a caterpillar turning into a butterfly.

This impression lasted at least into 1982, as Lawrence Miles and Tat Wood point out in their About Time reference series. The officially licensed magazine Doctor Who Monthly stated in a "Matrix Data-Bank" column that year that its readers should not confuse the "regenerations" of later incarnations with the "rejuvenation" of Hartnell into Troughton.

It was also not clear initially whether the renewal was a natural ability of the Doctor's as opposed to a process initiated by technology. In Power, the Doctor describes his renewal as a function of his TARDIS time machine, stating that "without it, [he] couldn't survive."

When Troughton left the series in 1969, the Doctor was renewed again, but this time it was forced on him by the Time Lords at the conclusion of The War Games, where it is referred to as a "change of appearance". Once again, this suggested that it was a superficial physical change, not one of personality, although Jon Pertwee's portrayal of the Third Doctor also differed quite substantially from Troughton's. In addition, this change is treated as a punishment rather than a natural process — the Second Doctor protests, "You can't just change what I look like without consulting me!"

It was only at the end of the Third Doctor's era, in Planet of the Spiders (1974), when Pertwee's Doctor turns into Tom Baker's Fourth Doctor, that the change is finally called "regeneration" and is explained as a biological process that occurred when a Time Lord's body was dying. It is also stated that following the regeneration the Doctor's brain cells would be shaken up and his behaviour would be "erratic" for a time, something that would be true for most subsequent regenerations.

As the series continued, more aspects of the regenerative process were introduced, but the basic concepts of regeneration as accepted by fans of the series today were only firmly established in the final scene of Planet of the Spiders. This notwithstanding, it is now generally accepted by fans (from an in-universe perspective) that the "renewal" of the First Doctor into the Second and the "change of appearance" of the Second Doctor into the Third were both part of the same process of regeneration.

Transitions
The regeneration "effect" was accomplished during the series' original run from 1963–1989 primarily through the use of video mixing. Originally, the plan was to have Hartnell collapse at the end of The Tenth Planet with his cloak over his face, which would then be pulled back to reveal Troughton in the next serial. However, vision mixer Shirley Coward discovered and took advantage of a malfunction in the mixing desk which allowed Hartnell's image to be overexposed to the point of almost whiting out the screen, then fading back in to reveal Troughton's face. This also meant that the regeneration scene could take place with both actors at the conclusion of The Tenth Planet, and Troughton was accordingly signed up to participate.

Subsequent regenerations retained essentially the same method, with or without additional video or make-up effects. The transition from the Fourth to the Fifth Doctor used an additional make-up effect representing a transitional form known as the Watcher, but aside from this, other regenerations in the original series run simply mixed the image of the incoming actor on top of the outgoing one. The transition from the Seventh to the Eighth Doctor in the 1996 television movie took advantage of the higher budget and modern computer animation technology to "morph" the features of Sylvester McCoy into those of Paul McGann.

With the exception of the transitions from the Second to Third and the Eighth to Ninth Doctors, each regeneration was shown on-screen, with the previous incumbent in the role symbolically "handing off" the character to the next. The Second Doctor was never seen to actually change into the Third, simply fading off into darkness at the end of The War Games and then stumbling out of the TARDIS, already regenerated, at the start of Spearhead from Space (1970).

The regeneration of the Sixth Doctor into the Seventh is the only time that a single actor took on the roles of two incarnations of the Doctor. Colin Baker declined the invitation to film the regeneration sequence at the start of Time and the Rani (1987) due to the circumstances in which the BBC dismissed him from the role. As a result, Sylvester McCoy had to don his predecessor's costume and a blond curly wig, lying face down, with the mixing effect to the Doctor's "new" features occurring as he was turned over.

The 2005 series, which revived the programme after a 16-year hiatus, began with the Ninth Doctor already regenerated, with no explanation given. In the documentary series Doctor Who Confidential, producer Russell T Davies explained his reasoning that, after such a long hiatus, a regeneration in the first episode would not just be confusing for new viewers but also lack dramatic impact, as there would be no emotional investment in the character before he was replaced. The regeneration of the Ninth Doctor into the Tenth at the end of "The Parting of the Ways" (2005) was seen, and also used computer effects to morph Christopher Eccleston into David Tennant. In the episode of Doctor Who Confidential accompanying the episode "Utopia", it was stated that the production team had decided that this would be a common effect for all Time Lord regenerations (the Master's in this case) rather than having a regeneration sequence chosen on a whim by the director.

In the series
The exact mechanism that makes regeneration possible is not stated in the television series, but it is generally assumed in the spin-off media that the ability to regenerate may be linked to what is known as the "Rassilon Imprimatur", the symbiotic nuclei of a Time Lord that bonds him or her to a TARDIS, and allows his or her body to withstand the molecular stresses of time travel (The Two Doctors, 1985). In "The Christmas Invasion" (2005) it was stated the regenerative cycle generates a large amount of energy that suffuses the Time Lord's body. As demonstrated by the Tenth Doctor, in the first fifteen hours of regeneration this energy is enough to even rapidly regrow a severed hand. In the moments following his regeneration into the Eighth Doctor, he possessed enough physical strength to batter a steel door completely off its hinges.

It is first stated in The Deadly Assassin (1976) that a Time Lord can regenerate twelve times before dying (thirteen incarnations in all). There are exceptions to this rule, however; when a renegade Time Lord known as the Master finds himself at the end of his regenerative cycle, he takes possession of the body of another person to continue living (The Keeper of Traken, 1981), although he was using the Source of Traken to bind his mind to the body. It may be that the Time Lords also have the ability to circumvent the limit — in The Five Doctors (1983) the Master is offered a new cycle of regenerations by the High Council in exchange for his help. The fact that the Master is inhabiting a non-Gallifreyan body at the time implies that it is possible to grant them to a non-Gallifreyan, albeit one inhabited by a Time Lord mind. In "The Sound of Drums" (2007) the Master is revealed to have been granted a new body by the Time Lords during the Time War with at least one new regeneration. Non-Gallifreyans are also seen to regenerate in Underworld (1978) and Mawdryn Undead (1983), but with adverse side effects. In Mawdryn Undead these appear to be the result of mishandling of stolen technology, but in Underworld they are implied to be the inevitable result of a limited technology that youthens, rather than changing, the subject's appearance, and regenerates 'the body, not the soul'.

The BBC's Series 4 FAQ suggests that now the Time Lord social order has been destroyed, the Doctor may be able to circumvent the limit on regenerations; it says: "Now that his people are gone, who knows? Time Lords used to have 13 lives."

In the Fourth Doctor story The Brain of Morbius, the Doctor participates in a mental ‘duel’ with another Time Lord. The machine to which their minds are connected begins to project the faces of the "losing" contestant’s regenerations in chronologically descending order. As the Doctor is overpowered by Morbius, the images change successively to those of the third, second and first Doctors, then eight further faces appear. The narrative does not definitively assert that these are past incarnations of the Doctor rather than of Morbius; other evidence from the series suggests they cannot be. The Doctor himself has numbered his regenerations on several occasions, each time intimating that the William Hartnell incarnation was the first. For example, it is explicitly stated by the Fifth Doctor in Mawdryn Undead that he has eight incarnations left, and in The Five Doctors Peter Davison's Doctor (introducing himself to the First Doctor) says that he is the fourth regeneration, meaning that there have been five of him. Again in The Five Doctors, the First Doctor refers to himself as the "original".

With regeneration also comes a change of personality. This is likely a side effect of the process of complete physical transformation, which includes an alteration of the brain chemistry and synaptic organisation. The viewing audience sees this most often and most dramatically in the differing quirks and personality traits of the Doctor's various incarnations. However, it appears that the Doctor's core personality traits of heroism and intolerance of injustice are still retained. The Doctor also sometimes goes through a period of physical and psychological instability (which has included partial amnesia, temporary manic depression and on one occasion an act of physical violence against his companion) following a regeneration, but it is not clear if this is true of all Time Lord regenerations, particularly since the Doctor's regenerations tend to happen due to stressful and violent situations. Regenerations have been known to fail, and may require assistance, technological or otherwise, or a period of recovery to successfully complete the process. The Brain of Morbius suggests that Time Lords other than the Doctor may experience difficult regenerations, since the Sisterhood of Karn had been supplying them with an "elixir of life" that could assist the process.

In some cases, future potential incarnations can achieve independent, though temporary, existence. In Planet of the Spiders, a Time Lord, K'anpo Rinpoche, creates a corporeal projection of a future incarnation which has such an existence under the name Cho Je until he regenerates into that incarnation. The Valeyard, a "distillation of the Doctor's evil side, who could potentially exist between the Doctor's twelfth and final incarnations", appears in The Trial of a Time Lord (1986) opposite the Sixth Doctor; the Valeyard is offered the Doctor's future regenerations which would "make his potential existence concrete". Another example is "The Watcher", who repeatedly appears to the Fourth Doctor in Logopolis (1981), and ultimately merges with him as part of his regeneration into his fifth incarnation.

The Time Lords' ability to change species during regeneration is referred to in the television movie by the Eighth Doctor in relation to the Master. This is supported by the implication by the Daleks that the First Doctor's apparently human appearance was not his true form (The Daleks' Master Plan, 1965) and the Fourth Doctor's Time Lady companion Romana's regeneration scene in Destiny of the Daleks (1979). In that scene Romana demonstrates an apparent ability to "try on" different bodies from a number of different species during her regeneration, before settling on a final, humanoid form which physically resembles Princess Astra of Atrios (see discussion below).

While explaining the process of regeneration to Rose at the end of "The Parting of the Ways", the Ninth Doctor suggests that his new form could have "two heads", or even "no head", although it is unclear if he is merely joking. In the 2005 Children in Need special, which takes place immediately after, the newly regenerated Tenth Doctor, while examining his new body, makes a point of checking that he has two arms, two legs and two hands, implying that regenerations can sometimes result in physically deformed or non-humanoid forms; whether this is also a joke is not clear. In "The Runaway Bride" the Tenth Doctor tells Donna Noble that being human is "optional" for him. The Doctor's regenerations have produced some strange effects though: in his first regeneration the Doctor's clothes change along with his body, the Third Doctor is seen sporting a tattoo of a snake (which Jon Pertwee had acquired while in the Navy) as of his first televised serial Spearhead from Space, the Doctor loses the ring on his little finger during his third regeneration (Jon Pertwee's wedding ring), the Doctor's shoes change along with his body after his fourth regeneration, and the Tenth Doctor can be seen with gelled hair immediately after the regeneration is complete. These can be presumed to be little more than production errors.

Whether or not Time Lords can recognise each other across regenerations is not specified in the television series. For example, in The Deadly Assassin an old classmate of the Doctor's, Runcible, is slow to recognize the Doctor in his fourth incarnation, and once he has, it then takes him a while to realize that his appearance has changed. However, in The Armageddon Factor (1978), Drax, another old classmate, recognises the Fourth Doctor immediately although they had not seen each other since the Academy (the Doctor takes a while to remember Drax, though). Shortly thereafter, in Destiny of the Daleks, the Doctor fails to recognize the yet-to-stabilize, newly-regenerated Romana. In The Twin Dilemma, the Sixth Doctor attributes old friend and fellow Time Lord Azmael's failure to recognize him to the fact that "I have regenerated twice since our last meeting." Yet in "The Sound of Drums" (2007) the Doctor states that Time Lords can "always" recognise each other, and recognises Professor Yana as the newly awakened Master on sight. However, in the mini-episode "Time Crash", the Fifth Doctor didn't recognise the Tenth Doctor on first meeting, thinking he was merely "a fan" who has sneaked into the TARDIS.

The series has suggested many times that regeneration is not guaranteed and can fail. After his cellular structure is decimated by the Metabelis crystals in Planet of the Spiders, the Third Doctor's regeneration requires "a little push" from fellow Time Lord K'anpo Rimpoche before it can proceed. As he succumbs to spectrox toxemia in The Caves of Androzani, the Fifth Doctor says, "I might regenerate... I don't know... It feels different this time...". He then hallucinates, seeing his former companions, encouraging him to fight and survive, before the Master overwhelms them all, telling him he must die. The 1996 TV movie showed the Doctor's regeneration delayed for more than three hours, with the Eighth Doctor later remarking that the fact his Seventh incarnation was under anesthesia at the time of his "death" could have "destroyed the regenerative process." There are also many episodes in which the Doctor openly doubts his survival, such as in the 2005 episode "The Unquiet Dead". Although, with the Eighth Doctor explicitly stating that he was "dead" prior to regeneration, it's unclear as to whether statements like that made by the Ninth Doctor in The Unquiet Dead might only be referring to the death of his particular incarnation. In The Mind of Evil the Master points a conventional firearm at the Doctor and threatens to "put a bullet through both your hearts", while in "Forest of the Dead", Professor Song warns that an impending electrocution would stop both the Time Lord's hearts, killing him. From these, it is apparent that a Time Lord can die if both his hearts stop. In "Turn Left" - an alternative history story - a UNIT member speculates that the Tenth Doctor is killed "too quickly for him to regenerate".

The Doctor's regenerations
As noted, the Doctor frequently experiences a period of physical and mental instability following regeneration and some post-regeneration experiences have been more difficult than others. Notably, the Fifth Doctor (in Castrovalva) begins reverting to his previous personalities and the Sixth Doctor experiences extreme paranoia, flying into a murderous rage and nearly killing his companion (The Twin Dilemma, 1984). The Eighth Doctor experienced amnesia as a result of post-regeneration trauma (the 1996 television movie); uniquely, the Doctor was 'not alive' at the time of this regeneration. The regeneration from the Ninth to the Tenth Doctor sees the Doctor unconscious for most of the next fifteen hours ("The Christmas Invasion"). The experience is also traumatic enough to cause one of his hearts to temporarily stop beating.

In the series four finale of the revived series, ("Journey's End"), an injured Tenth Doctor manages to avert a full regeneration by channelling "excess regenerative energy" into his severed hand, allowing him to heal without changing form. This is the first time the Doctor has gone through a partial regeneration. Later in the episode, the energised limb grows to form a new being - essentially a clone of the Tenth Doctor. The clone has the memories, mental capacity and outward appearance of the Doctor, but we are told he has only one heart and lacks the power to regenerate. Due to the proximity of companion Donna Noble during the generation of the arm, some of Donna's personality was absorbed into the clone's mind. At the same time, Donna inherits Time Lord traits, in particular the Doctor's vast intellect and technical know-how. The additional information soon begins to overwhelm Donna's human brain and at the end of the episode the Doctor has to remove all memories of her time with him in order to save her life.

The TARDIS appears to assist in the regenerative process. In addition to the second Doctor's explicit statement to this effect shortly after regenerating from the first, regenerating outside the TARDIS has never been shown to go particularly well. Of the four occasions on which this has happened, one is forced on him by the Time Lords (The War Games), one requires a Time Lord to give the Doctor's cells a "little push" to start the process (Planet of the Spiders), one needs the TARDIS's "Zero Room", a chamber sealed from all outside forces, to help him recover (Castrovalva) and the last occurs a few hours after he has actually "died" (The 1996 television movie). That last regeneration remains the only one that takes place significantly far away from the TARDIS, without any obvious interaction from other Time Lords. It may be noted, however, that in The Doctor's Daughter, Jenny, a woman created from the Tenth Doctor's DNA, dies and later reanimates in a process that has some apparent similarities to a regeneration some time after the TARDIS leaves her planet. She does not, however, change appearance.

Romana's regeneration
Romana's tongue-in-cheek regeneration scene in Destiny of the Daleks contrasts markedly with the Doctor's transformations. In the first episode of the serial, Romana undergoes regeneration, in the process trying out several different forms before choosing to adopt the appearance of Princess Astra, a character she encountered in a previous adventure (The Armageddon Factor).

Doctor Who television writer and script editor Eric Saward suggests in his 1985 novelisation of The Twin Dilemma (1984) that Time Lords can control the appearance of their next body if they trigger the regeneration voluntarily, but not if the regeneration is caused by death or injury. The Doctor Who Role Playing Game by FASA suggested that some Time Lords have a special ability to control their regenerations.

The fan reference book The Discontinuity Guide suggests that the various "try-ons" were projections of potential future incarnations like the K'anpo Rinpoche/Cho Je situation in Planet of the Spiders. Miles and Wood's About Time also mentions this along with theorising that the Time Lords had improved the technology of regeneration since the Doctor's time; Romana, being of a later generation than the Doctor, would therefore have finer control over the regenerative process in its early stages. Aside from the how of it, at least three attempts have been made in the spin-off media to explain the necessity for Romana's regeneration.
 * In the short story "The Lying Old Witch in the Wardrobe" by Mark Michalowski, published in the Big Finish Productions anthology, Short Trips: Companions, unknown to the Doctor, Romana suffers damage due to exposure to the Key to Time. Just as she is about to regenerate, a humanoid manifestation of the TARDIS, jealous of Romana, traps her in a force field. It proceeds to pretend to be Romana, changing into different forms until finally becoming a double of Princess Astra. This manifestation is the one who appears in Destiny of the Daleks. Realising the error of its ways after that adventure, it releases Romana, but not before making the female Time Lord assume the image of Astra.


 * The second explanation, which may or may not be consistent with the first, is given in the Gallifrey audio series. Gallifrey: Lies by Gary Russell reveals that Romana forced her own regeneration to prevent an ancient Gallifreyan evil called Pandora from gaining power over her (see also History of the Time Lords - Audio plays).


 * The third explanation is in the Fifth Doctor audio story The Chaos Pool by Peter Anghelides, which states that the creators of the Key to Time re-disguised its final segment as Romana, which is why she changed and why she chose Astra's form. It is possible that the previous explanation was arranged by the Key's makers to facilitate this one.

The Master's regeneration
The Master has regenerated once on-screen in the 2007 series episode "Utopia". After being fatally shot by the insectoid creature Chantho, the Master regenerates from the incarnation known as Professor Yana, played by Derek Jacobi, into the current incarnation, played by John Simm. Before regenerating, the Master expresses desire to become "young and strong" like the Tenth Doctor. The effect used for the Master's regeneration, though similar to the Ninth Doctor's, is notably brighter and more colourful, using an array of psychedelic colours. The Master also screams loudly during the process, implying that the Master's regeneration was painful, another dissimilarity with the Doctor's regenerations.

Previously, the Master has been shown to possess non-Gallifreyan bodies in order to extend his life. The first was a Trakenite named Tremas in The Keeper of Traken and the second was a human named Bruce in the TV movie. In The Deadly Assassin it is stated that the Master had in fact used up all his regenerations, hence his decrepit appearance in that serial. He is in fact attempting to use the artefacts of Rassilon to obtain a new cycle, but the process would destroy Gallifrey, so the Doctor intervenes. In The Five Doctors the High Council of Gallifrey offers the Master, who is now possessing the body of a Trakenite, a new regeneration cycle in exchange for his help. Although there's no indication he actually received this new cycle, in "Utopia" he regenerates naturally and in '"The Sound of Drums" he indicates that he had been revived by the Time Lords to fight the Time War, suggesting his life had indeed been extended.

In "Last of the Time Lords", the Master and the Doctor demonstrate that regeneration is not an automatic process, as the Master instead chooses to die after being shot by Lucy Saxon, despite the Doctor's pleas. It would not be until the 2009 Christmas Special that the Master would return.