The Heralds of Destruction (comic story)

 was the sole story of the Doctor Who: The Third Doctor comic book mini-series, published in 2016.

Summary
When something enormous crashes into Bedfordshire, the Doctor, Jo Grant, and the forces of UNIT under Brigadier Lethbridge-Stewart mobilise immediately – and find themselves in the middle of a pitched battle against a terrifying invader... But the shocking face that awaits their return to base may tip the whole world off its axis!

Part one
At the Fragrant Wayfarer, Jo Grant and Mike Yates enjoy some Taiwanese food before a call comes in for "Greyhound leader", swiftly ending date night. Back at UNIT HQ, the Brigadier ushers them both into Benton's waiting helicopter, saying that they have a Condition Black emergency. When Jo Grant asks about the Third Doctor, the Brigadier replies he's not answering his phone.

Across town, the Doctor is enjoying a spot of chess at the gentlemen's club before he is called away, racing off in Bessie. Back at the club, the Doctor's opponent keeps tabs on the Time Lord via a tracker before removing his mask, revealing himself as.

Arriving in Fairford, the Doctor barely dodges a shell before he picks up Benton who directs him to the mobile command centre. At the retrofitted church, the Doctor happily reunites with Jo before the Brigadier shows him footage of the invading aliens (who fired first), a race of robotic beings that the Doctor has never seen before.

Undettered, the Doctor attempts diplomacy, only to be struck by an energy bolt. Even with Jo's earlier warning about the compratively weak attacks, his lack of harm surprises the Doctor who suspects something larger is afoot before UNIT calls in air strike which destroys the invaders. As the dust settles, the robotic bodies begin reconsituting, using the rocks and asphalt as raw materials. The Doctor seizes a piece of a body, neutralizing its assimilation with his sonic screwdriver, and heads off to see Tom Osgood. After some tinkering with the man's field radio, the Doctor contains the robots in a force field before he and Jo rush off to his lab for analysis of the one robotic piece that they have.

Arriving back at headquarters, the Doctor is stunned by the spooked staff with Carol Bell directing him to his laboratory. The Doctor is furious that someone other than him and the tea lady was allowed in but as Bell shows, they followed his rules.

His guest is none other than the Second Doctor!

Part two
Though the Second Doctor is as cheery as ever, the Third grumbles as Jo questions why the Second Doctor doesn't seem familiar with them. After all, didn't they just part ways with him? Somewhat brusquely, the Third Doctor explains that two of the same Time Lord being together causes the younger version to forget the encounter. Then, the Second Doctor draws their attention back to the machine. Having been sent by the Time Lords, he explains that the invaders are each a colony of beings, much like a coral reef, which leads the Third Doctor to wonder what they want with Earth.

Back in Fairford, the command centre is visited by General Mayhew, with whom the Brigadier makes some minor pleasantries, before the General is shown the invading robots. After barking some commands, the Brigadier pulls a gun on the General and asks if he's responsible for the invasion, ripping off the man's face to reveal the Master. After asking what gave him away, tries to hyponitze the Brigadier, only for the man's iron will to resist the compulsion to obey.

Back in the lab, the Third Doctor orders the Master brought right to him before the machine part activates and rakes Jo. Though the Doctors are quick to deactivate it, Jo's back is already turning to metal. The nanites having begun to colonize her body. Leaving his previous incarnation to handle things with UNIT, the Third Doctor enters Jo's mind to have a word with the invading intelligence.

On the UNIT helicopter, the Master insists he's not the enemy. The enemy is someone that even the Doctor hasn't suspected before his mask flies outwards and begins suffocating the Brigadier. The masks, the Master explains, are pieces of his TARDIS, meaning they obey his mental commands. After shaking free of his shackles, the Master recalls the mask and jumps out of the helicopter, the mask forming a parachute.

Within Jo's mind, the Doctor is unsurprised to find hippie styling but most pleasantly surprised to find that Jo has no inner demons. After meeting Jo's inner self, the Doctor leads her an outlying well before a metallic tentacle arises and begins strangling him. In the waking world, the Brigadier enters, rather unsurprised to see the previous Doctor, before both Jo and the Doctor's bodies turn a metallic shade of silver, their expressions locked in pain and agony.

Part three
As the tentacle strangles the Doctor, Jo forms a book and strikes it, sending it slithering away. Without wasting any time, the Doctor leaps into the well after the invader. In the lab, the Second Doctor notes that, although the two are no longer in distress, the metallic invasion is nearly completed before he has an idea of someone who can help, running off to find them.

In the depths of Jo's subconscious, the Doctor finds the guiding intelligence and establishes a connection to it. The machine intelligence struggles to communicate in the Doctor's speech but manages to impart that it is angry and afraid as it is being confined and forced to be something it is not. With a wry smirk, the Doctor sympathizes. Until recently, he was imprisoned on Earth, even changed to fit in better, something he suspected was done so he would grow to like his cage. Yet now that he's free, he remains here, pretending to enjoy London. At this point, Jo makes herself known, and, with angry tears flowing, tells the Doctor to simply leave if he hates Earth so much. With a smile, the Doctor resumes his speech. He's still on Earth because his friends have made him want to stay and any smug pretentiousness, he reckons, is largely that an act his friends have come to expect.

With their friendship secured, the Doctor introduces Jo to the micro machines, now cognizant of their error. When looking at the invader's memories, however, the Doctor can find nothing before they appeared in Earth's orbit. Promising to help, the Doctor asks to be released.

In Fairford, Osgood notes that the signals from the micro machines have all calmed down. As the situation deescalates, Yates and Benton discuss the former's date with Jo with the former grumbling that he wishes the Doctor would just hurry up and leave Earth.

As Jo and the Doctor come too in the lab, the Brigadier helps the former up only for the Doctor to see right through his ruse. Almost amused, the Master casts off his mask before insisting that he's here to help. The Doctor will hear none of it and the two come to blows, Mercurian kung fu assuring the Doctor's victory. After the Brigadier is freed from the closet the Master stuffed him in, the Master is surrounded with the Doctor demanding to know more about the aliens. The Master chuckles, the machines are not aliens. At first, he was annoyed that an alien race, who hadn't asked him for help, was invading Earth but the arrival of the Doctor's previous self roused his suspicions. Revealing that he has multiple bugs in the lab, implanted by the perpetually unnoticed tea lady, he's made a rather interesting discovery about the Doctor's past incarnation. Having been burned by Time Lords before, the Master has learnt to keep an eye out for them and there's been no signs of any temporal incursions for months. So how did the Second Doctor get here? Thanks to a psychological scan however, the Master has managed to solve the puzzle.

Across town, the "Second Doctor" races in a jeep to Electronicon Ltd. and makes his way to the board of directors. In the conference room, he shows them blueprints for the TARDIS, along with other Time Lord technologies, before he steps out for a moment.

Horrified realization strikes the Doctor just as his doppelgänger re-enters the room, now in a three-pieced suit and feeling like Ramón Salamander once again.

Part four
to be added

Part five
to be added

Characters

 * Third Doctor
 * Jo Grant
 * Alistair Gordon Lethbridge-Stewart
 * Mike Yates
 * Waiter
 * John Benton
 * Tom Osgood
 * Micro machines
 * Carol Bell
 * Ramón Salamander
 * Dr William
 * Dr Draper
 * Dr Draper

Continuity

 * The Third Doctor and the Second Doctor have encountered each other not long before, as Mike Yates notes that the Third Doctor has recently regained the use of his TARDIS. (TV: The Three Doctors)
 * Jo tries to explain why the Doctor can't remember meeting his previous incarnation by saying that "things get all timey wimey". (TV: Blink, The Day of the Doctor, COMIC: Four Doctors)
 * The "Second Doctor" has a recorder. (TV: The Power of the Daleks)
 * Yates and Benton notes that they've never seen "Miss Heriot" again. (TV: The Invasion)
 * While discussing the possibility for time travel, Dr William mentions "Ingram's work at the Newton." (TV: The Time Monster)
 * Within the Time Vortex, a Reaper, (TV: Father's Day) a Vortisaur, (AUDIO: Storm Warning) and two Chronovores can be seen. (TV: The Time Monster)
 * Salamander was brought back to Earth during the events of TV: The Web of Fear.
 * The Master begins an interrupted statement ("Peoples of the universe! Please attend...") which he will eventually be able to finish on Logopolis. (TV: Logopolis) He will re-use the speech many times in his life. (TV: The Sound of Drums; COMIC: The Abominable Showmen)
 * The Doctor points out to Jo that he is not British but a "citizen of the universe". (TV: The Daleks' Master Plan)
 * Upon visiting the previous century, Mike starts yearning for a golden age. He will soon act on this desire by betraying UNIT and the Doctor when he joins the manipulations of Charles Grover. (TV: Invasion of the Dinosaurs)