Immediately after the TV movie, the Eighth Doctor walks about his TARDIS and, less than one page in, manages to completely lose his memory. To complicate matters, the Master is freed in the process, Eight runs into a girl named Samantha Jones at Totter's Lane and accidentally becomes the owner of a bag of crack cocaine, the police don't believe his name is "Doctor John Smith", and Rassilon appears as a vision and tells him to go seek out all his old selves.
The Doctor proceeds to do exactly that, hoping to regain his memory. Each time he gets near a previous incarnation, time stops for just a few moments, allowing him to remember more and more. He stops the First Doctor from killing a caveman and convinces the Second Doctor to summon the Time Lords.
The Third Doctor, Jo and the Brigadier are still on the trail of the Master, and — after an elaborate car/helicopter chase — track him down to Devil's End. The Eighth Doctor shows up well after the action, and instead simply chats with the UNIT gang for a while. Three, however, does not cope well with seeing an older self with a fully operational TARDIS, and briefly considers a few very not-heroic solutions to the situation. The two part amicably after Eight promises that Three's life will soon get better. The Fourth Doctor and Romana manage to get captured by some rogue vampires, and Four lets them drain his neck and wrists, giving Romana a chance to escape. She and Eight break into the manor, free Four, set the whole thing on fire and save Four's life with a blood transfusion.
In the middle of all that, Lady President Flavia takes an interest in the Doctor's unexplained meddling with the Web of Time, and gets a few Time Lords on the case. One of them considers this a perfect opportunity to secretly get in touch with the Celestial Intervention Agency and see if they can kill the Doctor together.
The Fifth Doctor, Tegan and Turlough try to have a cricket match on the Eye of Orion, and get rather rudely interrupted by a Raston Warrior Robot, an army of (very confused) Sontarans, and a Drashig, all sent by said vengeful Time Lord. Five and Eight manage to confuse the Raston Warrior Robot into submission and make it slaughter the Sontarans — after which they teleport the Drashig straight to Gallifrey, where it promptly eats the guy who sent it.
The Sixth Doctor, halfway through his trial, gets sentenced to death by the Valeyard and is saved in the nick of time by Eight — who is rather confused about the whole thing, since he definitely doesn't remember being executed. He deduces that the Valeyard is trying to force an alternate timeline. With some truly magnificent Bothering by the Book, the Doctors claim the legal power that comes with being an ex-President, and force an official inquiry into the Valeyard's actions. The long since deposed Lady President Flavia is very shocked to discover a political ploy that involves the Master, Sabalom Glitz, the Outsiders, and the current Lord President. While Six merges back into his proper timeline version and vanishes, Eight prevents the collapse of Gallifreyan society by simply walking into Rassilon's tomb and asking nicely if he can borrow Borusa for a bit. Borusa, revived by Rassilon, saunters into the Panopticon and reclaims his position as the Lord President.
In the aftermath, the Eighth Doctor rescues the Seventh from a rogue spider on Metebilis III, and Seven — realising that his regeneration is almost over — decides to simply let fate decide when and how his life will end, instead of despairing over being alone. The Master, meanwhile, has managed to secure himself a goosnake thing and vworps over to Skaro to intentionally get himself killed.
After a bit of prompting from Rassilon, Eight goes back to Totter's Lane, solves the loose ends of the cocaine plot thread without much effort, and picks up Sam as a companion.
Lady President Flavia is really very confused at the whole story. All she knows is that she was President, then Borusa came back for a bit, then she became President again, and suddenly — as if in a dream — the Doctor seems a lot more important in her life.
Tropes present in The Eight Doctors include:
- The Aggressive Drug Dealer: The villain of the Very Special Subplot.
- Author Appeal: Terrance Dicks spends a lot of time writing Three, as well as his E-space vampires.
- Bait-and-Switch: The first few chapters focus on Sam's life, a drug deal, two Suspiciously Similar Substitute characters based on Ian and Barbara, police procedings, and quite a number of side characters. All this is promptly forgotten about once Eight starts his quest, and the whole thing becomes little more than a Brick Joke... until the Doctor remembers that crisis at the end and is sent back by Rassilon to tie up the final loose end.
- Big Bad Wannabe: Ryoth had some links to Goth and Borusa in past regenerations, and attempts to get Flavia dismissed by accusing her of ignoring the risks of the Doctor's current visits with his past selves. However, Flavia's response makes it clear to Ryoth that the only reason he hasn't been arrested yet is that he was just too small-time to be bothered with so far, and if he keeps drawing her attention that will change.
- Book Ends: The Eighth Doctor says (to the Brigadier) "Let's just say that I'm a Doctor. There's more than one, you know. Clearly, I'm not the one you were expecting." The lines are repeated almost word-for-word by this Doctor in his final appearance.
- Bothering by the Book: Eight and Six manage to uproot all of Time Lord society simply by being clever bastards with a working knowledge of Time Lord law.
Then they put their feet up on the Lord President's desk and ask for lunch. - The Cameo: Benton appears for about a paragraph.
- Calling the Old Man Out: The amnesic Eighth Doctor basically does this to his own first incarnation, arguing that his morality is still intact even if he currently doesn’t consciously remember anything more than what his first self has experienced to date, denouncing his motives for leaving Gallifrey and encouraging him to be better than the Time Lords he abandoned.
- Chekhov's Gun: The Master's Shrink Ray.
- Continuity Porn: The Eighth Doctor visits six of his past selves during or just after crucial adventures in their lives (he visits the Seventh at a point between the end of the series and before Seven reconfigured the control console).
- Continuity Snarl: A few examples of this compared to the New Adventures and the Missing Adventures, such as the Eighth’s memories of the Third Doctor’s life featuring no reference to his non-televised adventures, but a particularly significant omission is Borusa being freed during the Sixth Doctor’s era when the New Adventure Blood Harvest, which was also by Terrance Dicks, saw Borusa being released when the Seventh Doctor was active.
- However, this could be explained as Eight Doctors ends with a note from Gallifrey's historical records stating that Borusa just disappeared after leading the political reforms necessary after the Doctor’s trial. This creates the possibility that he returned to Rassilon to continue his punishment as he didn’t feel ready to be released yet, eventually achieving redemption in Blood Harvest.
- Heel–Face Turn: Borusa is a whole lot calmer after his extended stint in Rassilon's tomb, and has even been regressed to an earlier incarnation.
- Help Yourself in the Future: Whether giving his past selves advice or saving them from some direct threat, the Eighth Doctor's presence always serves to aid his younger incarnations at some crucial moment.
- Jumped at the Call: Sam makes it clear that she wants at least one trip in the TARDIS once she gets inside.
- Let's You and Him Fight: When the Fifth and Eighth Doctors are almost captured by a squad of Sontarans, they deal with the problem by tricking the Sontarans into reactivating a Raston Warrior Robot, while tears through the Sontarans before the squad commander manages to tear the Robot's head off in his dying moments.
- Nice Job Breaking It, Hero: In a loose sense; while the Eighth Doctor saves his other six selves from threats they were already facing, the Fifth is only in danger because certain parties on Gallifrey were anxious about Eight visiting his past selves and chose to attack him as he was visiting his fifth incarnation.
- Odd Friendship: Six and Eight get along surprisingly well.
- Other Me Annoys Me: As with any multi-Doctor story, the current Doctor's relationship with his past selves varies. The first three Doctors resent Eight giving them advice, particularly when his lack of memory of their future means that he can't know he's giving them good advice, and the Fifth is annoyed when the Eighth shows up in the middle of an attack, although he soon works with his older self to solve the problem. The Fourth and Sixth get along with the Eighth well enough, but this can be justified as Eight showing up in time to literally save their lives, and while the Seventh is cordial to his successor, Eight is uncomfortable as he knows that Seven's regeneration is imminent and his natural desire to help is tempered by the knowledge that doing so could erase himself from existence.
- Refuge in Audacity: Borusa got trapped for eternity in Rassilon's Tomb in the massive anniversary special "The Five Doctors". Eight saves the day by strolling right back into that tomb and politely asking Rassilon to loan him Borusa for a while, even offering to take his place if Borusa reverts to type.
- Shout-Out: The Coal Hill scenes at the beginning, particularly those set in "Coal Hill Police Station", are a very blatant nod to cop show The Bill.
- Small Name, Big Ego: Back on Gallifrey, Ryoth- a past associate of Goth and Borusa- attempts to use the Doctor's current visit to his past selves to start a political uprising, but it's subsequently made clear that Ryoth doesn't have a leg to stand on and he's only been allowed to remain free despite his political associations because he's just too small-time to be bothered with.
- Stable Time Loop: It's revealed at the end that the Eighth Doctor was allowed to visit his past selves by Rassilon himself, Rassilon using the Doctor to tie up some "loose ends" in the timestream.
- Summon Bigger Fish: Eight eventually gets thoroughly fed up with all the Time Lord bickering, and turns to Rassilon, asking if he can borrow Borusa for a bit.
- What the Hell, Hero?: Three briefly considers killing Eight and taking his TARDIS. Being stuck with UNIT is really taking its toll on him. Three being Three, he very calmly and matter-of-factly discusses the possibility with Eight, who assures Three that the block on his TARDIS will be lifted very soon. (Three episodes later, in fact.)
- Written-In Absence: Adric is asleep in the TARDIS during the Fourth Doctor's segment, while K9 attempts to plot a route out of E-Space.
