The Eighth Doctor, a Byronesque figure who is arguably the most human and romantic of all of his incarnations, encouraged those around him to seize life instead of withdrawing from it. He also seemed to enjoy giving people hints of their own futures, probably to prod them into making the right decisions. It is unclear if the eighth Doctor's knowledge of people's futures comes from historical expertise, psychic power or precognitive ability.
As with the Fifth Doctor, the debonair Eighth Doctor's youthful, wide-eyed enthusiasm actually hid a very old soul with perhaps a darker side. In fact, whereas the Eighth Doctor of the audio plays (voiced by McGann) and the comic strip hew closely to the television movie Doctor, the Eighth Doctor of the novels exhibited what was, at times, a much darker personality, perhaps due to the rather traumatic adventures that he underwent.
Fans have also been divided on the Eighth Doctor revealing that he is apparently half-human on his mother's side. In the Tenth Doctor story "Human Nature" it is revealed that Time Lords have the technology to rewrite their DNA. The BBC novels have referred to the issue, sometimes explicitly and sometimes obliquely. In the final Eighth Doctor novel, The Gallifrey Chronicles, it is implied that the Doctor's mother is a human woman named Penelope Gate, who appeared in a Virgin seventh Doctor novel called The Room with No Doors.
In all his iterations, the Eighth Doctor has proven extremely prone to bouts of amnesia, a tendency apparently inspired by the plot of his sole television appearance. He also demonstrates, in his first and only televised appearance, a penchant for sleight of hand. He manages to "lift" or pickpocket various items from certain people he meets during his first adventure.
After the Seventh Doctor was caught in the crossfire of a gang shoot-out in 1999 San Francisco he was taken to a hospital where surgeons, confused by his double heartbeat, attempted to correct a non-existent fibrillation. Their efforts instead "killed" the Doctor, triggering a regeneration into his eighth incarnation. At the time of his injury, the Doctor had been transporting the remains of his long-time nemesis the Master from the planet Skaro to Gallifrey.(Although it's interesting to note that in Remembrance of the Daleks, featuring the Seventh Doctor, Skaro was destroyed by the Hand of Omega). The Master, however, was not completely dead, and was able to possess a human form. In an attempt to steal the Doctor's remaining lives, the Master opened the Eye of Harmony within the TARDIS, and nearly destroyed the planet Earth as people celebrated the end of the millennium. However, with the aid of Dr Grace Holloway, the Doctor was able to stop the Master's plan; the Master was sucked into the Eye, apparently dying once and for all. The Master would, however, return in "Utopia".
The exact circumstances of the Eighth Doctor's regeneration into the Ninth have not yet been revealed. An off-hand remark by the Ninth Doctor in the 2005 episode "Rose" (commenting on the size of his own ears) suggests that the regeneration took place shortly before that story.
Almost as soon as he'd left San Francisco, the Doctor had another brief attack of amnesia, caused by a final trap of the Master's. To regain his memories, the Doctor was forced to visit all seven of his past selves and help them out with some crisis or another, at the same time acknowledging the responsibility his role gave him. Having regained his memories, the Doctor met a late twentieth-century Coal Hill School student named Samantha Jones; shortly after their encounter, the Doctor left her alone at a Greenpeace rally.
For a time, the Doctor adventured with an Ice Warrior named Ssard and a human woman named Stacy Townsend, who fell in love with each other; some while after they parted ways with the Doctor, the two invited him to serve as best man at their wedding (Placebo Effect). He also, at some point, teamed up with his old companion Bernice Summerfield, Brigadier Lethbridge-Stewart and UNIT to combat an Ice Warrior occupation of Great Britain.
Eventually, three years after his departure and one hour after he left, the Doctor returned to the Greenpeace rally. With Sam collected, the pair spent a great period wandering together, facing dozens of adventures. During their travels, Sam and the Doctor became aware of a great War, looming in the future of Gallifrey — a war between the Time Lords and an as-yet-unidentified Enemy, with dramatic and disturbing consequences. While exploring the subject, the Doctor discovered that his Sam was not the original Samantha Jones; rather, her biodata had been manipulated by an outside agency with the intent to mold her into a prosaic distraction for him (Alien Bodies). Ultimately this plan proved a failure, as Sam developed into a much more strongly-willed companion than intended; at one point she spent three years avoiding the Doctor, so as to cope with a crush she had developed on him.
The close dynamic between the pair was shifted with the introduction of Fitz Kreiner, a sixties bar singer incorrectly suspected of matricide. Fitz took on the role of a sort of younger brother to the Doctor, placing the Time Lord on as high a pedestal as Fitz had ever known. Eventually Fitz found himself abducted by Faction Paradox, a "time-travelling voodoo cult", and brainwashed into their legions. When the Doctor realized that a Faction member he had encountered was a biomass copy of Fitz, he used the TARDIS's telepathic circuits to restore Fitz's memories and identity to the clone.
With both Sam and Fitz gone — Sam's creators having been established as the Faction — the Doctor continued his travels with the clone Fitz and Compassion, an ex-Faction agent implanted with an interface that the Doctor found compatible with his TARDIS. Unbeknownst to the Doctor, the Faction — with the aid of the original Fitz — had changed his history, triggering his third regeneration ahead of schedule and infecting him with a time-release virus that, in his eighth incarnation, would transform him into a Faction member (Interference: Book One and Two).
Eventually, Compassion's implant triggered her unexpected mutation into a sentient Type 102 TARDIS, specifically the "mother" of the TARDISes that would be used in the pending War. With this knowledge, The Time Lords — led by Romana, now in her third incarnation — attempted to capture Compassion, for use as breeding stock in preparation for the War. In response, and in light of the apparent destruction of his old TARDIS, the Doctor and Fitz retreated into Compassion (The Shadows of Avalon).
The Doctor and Fitz travelled in Compassion for some time, until the machinations of Faction Paradox came to a head back on Gallifrey. As it turned out, in the new timeline triggered by the Doctor's infection, the Doctor was destined to become "Grandfather Paradox", the mythical founder of Faction Paradox. The only factor keeping the original sequence of events in play was the Doctor's TARDIS — which had rebuilt itself after its apparent destruction on Avalon, and had now materialized in a twisted form above Gallifrey, holding within itself the Doctor's original reality.
In a final confrontation with his future self, the Doctor resolved the timeline conflict by channeling the TARDIS's built-up energies through its weapon systems, thereby destroying both the Faction Paradox fleet and Gallifrey itself. In so doing, the TARDIS was able to rewrite the altered timeline with the original one that it "remembered". As a side effect, however, the Doctor’s entire memory was erased — apparently from the trauma of the event (The Ancestor Cell).
To give the Doctor time to recover and the TARDIS time to regenerate from the extensive damage it had suffered, Compassion dropped the Doctor off on Earth in the year 1889; she then delivered Fitz to 2001, with the intent that he wait for the Doctor to catch up to him. With that, Compassion departed for parts unknown. Back in 1889, meanwhile, the Doctor awoke in a railway carriage to discover no memory as to his real identity, and no possessions save a small, shapeless box — what was left of the TARDIS — and a note, simply stating "Meet me in St. Louis', February 8th 2001. Fitz".
Despite his amnesia, the Doctor retained a wide general knowledge. However, he also showed an uncharacteristic callous streak — easily allowing others to die, if the situations demanded it. (The Burning). To contrast, he was capable of feeling unusually poignant warmth, even dating a woman in the 1980s, and adopting a young girl named Miranda, a Time Lady from the future (Father Time).
Unsure what "St Louis" was intended by the note, the Doctor created his own in London: the St Louis Bar and Restaurant. As 2001 rolled around, Fitz indeed turned up there to meet him. With the aid of new companion Anji Kapoor, the Doctor and Fitz completed the TARDIS's regeneration, dealt with a race of invading aliens, then set back again to exploring time and space (Escape Velocity).
With his freedom restored, the Doctor chose to counteract his extended exile by seeking as much non-human company as possible. During this period, the Doctor encountered all manner of unusual beings — from a species that a cursory glance resembled the Earth tiger (The Year of Intelligent Tigers), to water spirits, to talking apes from another dimension. Though at times the Doctor seemed somewhat cold — as when he seemed more concerned about damaged plums than a dead man (Eater of Wasps) — he retained his passion for life in all forms. Although his amnesia remained a bother, the Doctor acknowledged that whatever had happened to him had happened for a reason, and he might as well make use of the advantages it offered.
Only a few months after resuming his old lifestyle, the Doctor faced another radical change: the loss of his second heart. As it happened, the heart served as a bond with Gallifrey; with the planet gone, the heart had begun to fester within the Doctor's body, pumping it with poison.
A man named Sabbath, an eighteenth-century secret agent gifted with time travel abilities, excised the blackened organ, both saving the Doctor's life and robbing the Doctor of some of his higher Time Lord abilities (his respiratory bypass system, his ability to metabolise toxins). It transpired that Sabbath was actually after the heart for his own purposes: when implanted into Sabbath's own chest, it imparted upon him those same Time Lord powers. An unexpected side effect of this experiment was that so long as the Doctor's heart remained within Sabbath's chest, the Doctor himself remained practically invulnerable to harm (though any injury sustained by the Doctor would weaken Sabbath).
Eventually, after a woman Sabbath loved sacrificed herself to save the Doctor from a malfunctioning time machine, Sabbath tore out the Doctor's second heart, allowing the Doctor to begin growing a new one.
Shortly after the restoration of his heart, the Doctor found himself locked in a desperate struggle with Sabbath as, along with his mysterious business associates, Sabbath hatched a plan to destroy all alternate realities. Sabbath believed that time travellers like the Doctor, every time they landed somewhere, created an alternate reality where they didn't show up, and that the universe was unable to support so many alternates without suffering damage; therefore, he attempted to trigger an explosion at Event One — the Big Bang — that would erase all alternate universes and leaving only one possible timeline. However, Sabbath's allies had been lying to him; in reality, Time would only split if absolutely necessary, and even then, it was nearly impossible to travel between alternate realities. Effectively, all that would be wiped out was free will itself...
The explosion at Event One was averted, but instead, what occurred was reality starting to 'slide' between histories, each reality fighting to become the dominant one. Along with new companion Trix, the Doctor, Fitz and Anji travelled through the realities, the Doctor being forced to erase at least two of them in order to restore the original reality. During this adventure, the Doctor appeared to become a bit more cold and calculating, sacrificing an innocent man to escape a pocket universe and even leaving alternate versions of Fitz and Anji to die in order to preserve continuity. However, in the end, their sacrifices paid off, the Doctor managing to stabilise reality by resolving a paradox that had been hanging over them since the beginning of the crisis, and then, with Sabbath's help, they confronted his masters; the Council of Eight, mysterious beings who gained power by foreseeing likely future events and then ensuring that they came to pass. The Doctor, as a rogue element existing outside of Time, was the only unpredictable factor in their universe, and was thus the only person who could stop them. Ironically, it was Sabbath himself who gave the Doctor the edge needed to stop the Council; realising that one of the Council members expected Sabbath to shoot him with a weapon designed to send the subject into the Time Vortex, Sabbath instead shot himself, condemning himself to eternal agony just to give the Doctor a chance to outmaneuver the Council and save creation from them. The move succeeded, and the Council's crystal space station was destroyed.
Some while after this, the Doctor was captured by Marnal, one of the few surviving Gallifreyians, and accused of destroying Gallifrey. Although Gallifrey had been all but wiped from history by the Doctor's actions, Marnal was able to jury-rig a Time Space Visualiser in order to witness the Doctor actually push the button as he faced off against the Grandfather, although there were about three minutes where the Doctor's activities in the TARDIS were unaccounted for. Reflecting on his discoveries in the TARDIS, the Doctor, along with the aid of K9 (who had been transported into a hidden area of the TARDIS and trapped there following Gallifrey's destruction) realised that his memory loss hadn't been caused by the trauma of destroying Gallifrey; in fact, the Doctor had wiped his memories in order to give his mind space to store the contents of the Matrix within his brain, compressed down so he wouldn't be driven mad by the voices of all the dead Time Lords within him, his own memories presumably stored somewhere else in his mind, given his occasional flashes from his past. However, right then, the Doctor had more immediate worries; namely, saving Earth from a species of massive fly-like aliens called the Vore, who would soon have the power to devour the planet. As The Gallifrey Chronicles ended, the Doctor, Fitz, and Trix dove into the Vore mountain, the Doctor equipped with a plan to stop the Vore and save the world.
Sometime after the events in San Francisco, the Doctor found himself wandering alone through the Vortex. In the wake of a Vortisaur attack, he was forced to land on Earth, in October 1930, aboard the doomed R101 airship. Aboard the vessel, the Doctor met a young adventuress by the name of Charley Pollard. In the course of his adventure, the Doctor saved Charley's life and took her aboard the TARDIS as his latest companion (Storm Warning). Though done in good faith, the Doctor soon understood that Charley's rescue would have much greater impact upon the timestream.
For two "seasons" of audio adventures, Charley's continued existence despite established history being in part contingent on her death on the R101 formed a rough plot arc in which the universe became infected with "anti-time", culminating in a conflict with the wraithlike Never People and the Doctor choosing to sacrifice himself and his TARDIS by absorbing anti-time energy and transforming into the bogeyman Zagreus. This was only resolved when, restored to sanity but still infected with anti-time, the Doctor chose to sacrifice himself for the sake of Charley and the universe as a whole by removing himself from space and time, plunging into a divergent universe, of which he had no knowledge or frame of reference and in which there was no concept of linear time (Zagreus). Charley stowed away on his TARDIS, in a sense nullifying the Doctor's sacrifice by again placing herself in danger; for a time, this fact caused great friction between the characters and personal angst for the Doctor.
For another two seasons, the Doctor, Charley, and a new companion by the name of C'rizz, explored the divergent universe, gradually unravelling a deep plot designed around the Doctor by Rassilon, founder of Time Lord society. Eventually, with the aid of his companions, the Doctor escaped the trap built for him, overcame his emotional burden, learned that he had been purged of Zagreus and returned to his normal universe with Charley and C'Rizz in tow (The Next Life).
Following that point, which coincided with the end of the official Big Finish "seasons" in light of the return of Doctor Who to television, the trio wandered freely. The only continuing plot element involved C'rizz and his unusual, potentially destructive psychological development. This culminated in C'rizz's death (Absolution) which led Charley to also wish to leave the Doctor's company. Whilst the Eighth Doctor presumably thinks Charley has died (The Girl Who Never Was), she has in fact joined the Sixth Doctor (The Condemned) suggesting that when the Eighth Doctor first met Charley he already knew her in some form. However, in a Big Finish Productions podcast, executive producer Nick Briggs , when speaking on this development, confirms that the Eighth Doctor in fact does not know Charley at "their" first meeting, which itself strongly suggests that when the Sixth Doctor and Charley ultiamtely part company any memory on his part of their adventures will either be altered or erased. Briggs further hints that an endpoint to this storyline has already been decided.
It has also been revealed (in Terror Firma) that prior to meeting Charley, the Doctor travelled with at least two other companions — a brother-and-sister pair (Samson and Gemma Griffin) — of whom the Doctor's memories had been erased by Davros, as part of an elaborate revenge plot.
In September 2006, Doctor Who Magazine announced a new audio miniseries featuring the Eighth Doctor and new companion Lucie Miller (played by Sheridan Smith), set later in the character's chronology, after he has parted ways with Charley and C'rizz. Produced by Big Finish Productions, the miniseries was broadcast on BBC7; they began on New Year's Eve 2006 and ended on the 18th February 2007. The miniseries consisted of eight episodes, constituting six stories (the first and last stories having two parts).These are Blood of the Daleks, Horror of Glam Rock, Immortal Beloved, Phobos, No More Lies and Human Resources. In this series, the Time Lords have placed Lucie Miller in the Doctor's care as part of a "witness protection programme", contrary to the wishes of either the Doctor or Lucie. A second series of adventures featuring the Doctor and Lucie will be released monthly on CD by Big Finish Productions beginning in January 2008.
In the Doctor Who Magazine comic strips, at an unstated time after his regeneration (and after an adventure in the 1930s involving Fey Truscott-Sade and psychic weasels), the Doctor revisited the town of Stockbridge. After being caught up in the games of the Celestial Toymaker, he picked up a new companion in lively sci-fi fan Izzy Sinclair. The two of them were soon caught up in the machinations of the Doctor's old enemies the Threshold, a mercenary organisation. The Threshold attempted to manipulate the Doctor into stopping the Daleks gaining access to the multiverse (which would kill an artificial solar system as a side-effect) and dying in the attempt, but were outmaneuvered. Unknown to him, they implanted a device in Fey Truscott-Sade so that they could use her as an unwilling spy when she next encountered the Doctor. She did so in 1939, assisting him and Izzy against the vampiric Varney; the Doctor was left infected with a deadly bacillus, and he had to be taken to Gallifrey to be cured, luring him into a battle against a Time Lord cult called the Final Chapter.
Working out that the Threshold were using Fey as a spy, the Doctor and his old comrade Shayde faked a regeneration. The Threshold was conned into believing they were facing a vulnerable new Doctor (Shayde in disguise), allowing the real Doctor to infiltrate their base. While he and his friends were too late to stop the Threshold from destroying every single spacecraft in the universe, they were able to bring about the organisation's destruction before it could profit. Fey returned to her time, having also bonded with Shayde to save his life.
Unknowingly, the TARDIS had been taken over by the Master, who was manipulating events to gain the power of the omniversal Glory. The Doctor was specifically sent to times and places that would undermine him - discovering he had upset the course of Grace Holloway's life in 2001, encountering an alien race with motivations uncomfortably similar to his which caused death and horror 17th Century Japan, and almost killing the benevolent Kroton by mistake. (A slight diversion between events saw the Doctor and Izzy team up with the actor Tom Baker and other 1970s television actors against Beep the Meep in 1979.)
In 17th Century Japan, the Doctor's attempt to save the life of samurai Katsura Sato, a friend of Izzy, left the man inadvertently immortal and thus robbed of both an honourable death & any sense of empathy. The Master later came for Sato, when he was mentally vulnerable, and gave him a fake religion to focus his mind on; Earth's history was altered as Sato, renamed Lord Morningstar, and his Church of the Glorious Dead conquered the planet, creating a technological advanced, highly brutal planet of jihadists. The Doctor, Izzy and Kroton wandered into their invasion of the museum planet Paradost; while the Doctor faced the Master over the Glory, Izzy and Kroton spent weeks on the occupied world. The Doctor was defeated, only for the Master discover he was not able to access the Glory, as instead Kroton and Sato had been the ones prophesised to battle for it. Kroton won the Glory and history was reverted, and the Doctor and Izzy took a well-earned break.
During a battle against the body-stealing Ophidians and their gigantic snake-shaped techno-organic warship, the Doctor and Izzy encountered a brash and adventurous fish-woman called Destrii. While seemingly friendly and bonding with Izzy, Destrii was secretly on the run and she swapped bodies with Izzy to cover her escape; when Destrii was seemingly killed, Izzy seemed trapped within an alien body. The Doctor's next few journeys were spent trying to help her in this situation, both in coming to terms with the change and finding out what her new body's abilities were. Frida Kahlo helped Izzy mentally deal with the change, but the attempt at testing Izzy's abilities led her and the Doctor into a turbulent encounter with the humanised Daleks he had created in his second incarnation. Unable to prevent their tragic end - self-destructing to escape the machinations of the malevolent psychic Kata-Phobus -, the two of them were distracted and caught off-guard when Helioth and Hassana, two of the energy-beings called the Horde, abducted Izzy thinking she was Destrii.
The Doctor went on a relentless search to rescue his friend, with the help of Fey/Shayde and by forcing cooperation from Destrii, still alive in her stolen body. His quest led him to the planet Oblivion, a surreal and brutal world ruled by Destrii's mother, the Matriax. Izzy was rescued and returned to her original form, while Oblivion's court system and the menace of the Horde were both destroyed, leaving Destrii free to leave her world and explore the universe with her rougish uncle Jodafra. However, Izzy had decided she wanted to return home to her family, and the Doctor was left alone.
Feeling slightly morose, the Doctor was cheered up by an unknowing encounter with his old companion Frobisher and went on several 'holiday' adventures on his own. He eventually re-encountered Destrii and Jodafra in America during the 19th Century, where the upcoming clash between General Custer and Chief Sitting Bull was interrupted by Jodafra's machinations involving the monstrous wendigo. Jodafra had made a deal with the creature: power in exchange for being fed children. Unable to stomach this and with the Doctor urging her to listen to the spark of decency in her, Destrii helped the Doctor stop her uncle. In revenge, she was left beaten and abandoned, and the Doctor took her in as a probationary companion. Together, the two of them teamed up with MI6 and faced an invasion of early 21st Century Earth by time-travelling Cybermen; they were preparing to chemically overload the emotions of humans and thus make them willingly surrender to have their emotions removed by conversion. The Doctor destroyed them through use of the Time Vortex (similar to the later "The Parting of the Ways"), almost surrendering to it but giving up its power to save Destrii.
In 2007, Panini Books published Doctor Who: The Flood, the final collection of comic strips featuring the Eighth Doctor in Doctor Who Magazine. The book includes the essay "Flood Barriers" by strip editor Clayton Hickman in which he reveals that Russell T. Davies had authorized the comic strip to depict the regeneration of the Eighth Doctor into the Ninth Doctor at the end of the 2004-2005 arc, The Flood. The cause of the regeneration would have been the Doctor's exposure to the Time Vortex in his efforts to destroy the Cybermen (the same cause that triggered the later Ninth to Tenth Doctor regeneration in Parting of the Ways). Destrii would have witnessed the regeneration and would have continued to travel with the Ninth Doctor in a proposed Year One arc. When Davies vetoed the Year One arc and indicated the Ninth Doctor could only be shown travelling with Rose Tyler, Hickman and writer Scott Gray eventually decided not to depict the regeneration as they would have been unable to give Destrii a proper departure. The Panini collection includes the original script for the regeneration sequence, as well as never before published art showing the regeneration itself.