The one where the Doctor regrets losing the scarf.
Mostly notable for being the first time British Airways allowed filming aboard a Concorde,note "Time-Flight" is one of the sillier stories of Classic Who.
On the TARDIS, Tegan and Nyssa complain to the Doctor for letting Adric die. However, the discussion of Adric gets cut short when the TARDIS crew accidentally ends up at Heathrow Airport. Tegan's happy to be finally back home, and the Doctor, checking the paper for the latest cricket news, avoids arrest by simply telling the airport crew to call UNIT and verify his credentials. When asked, UNIT immediately tells the airport's board members to brief the Doctor on the mysterious case of a missing Concorde.
As it turns out, the Concordes are suddenly vanishing to the Jurassic era, so the Doctor, Nyssa, and Tegan follow the same flight path aboard a second Concorde, and appears to land safely back at Heathrow. However, the Doctor, monitoring the flight in the TARDIS, reveals they are 140 million years in Earth's past; a strong psychokinetic field is projecting the illusion of Heathrow to the humans. Outside, they spot the first Concorde, its crew and passengers under the assumption they are at Heathrow. However, they are performing slave labor under the control of Plasmatons, humanoid blobs of protein held together by the psychokinetic field.
One of the passengers, Professor Hayter, reveals he had seen through the illusion, and explains that a mysterious Oriental-like mystic named Kalid is controlling the psychokinetic field from a nearby Citadel, brainwashing his fellow passengers to try to break into a central chamber contained at the Citadel. As they learn of these events, they observe the passengers taking the TARDIS back to the Citadel.
As the group approaches the Citadel, Nyssa develops an empathic connection with the energy source, and Kalid erects a psychokinetic shield around her, preventing her from moving. As Tegan stays with her, the others continue on. At the Citadel, the Doctor goes off alone to find Kalid, learning that the mystic is seeking to gain direct access to a power source within the central chamber. When Stapley, the second Concorde's captain, and Hayter start to disrupt Kalid's control on the passengers, Kalid redirects his psychokinetic field to enforce the illusion; this causes the field around Nyssa to fall. Nyssa and Tegan continue to the Citadel. Along their way, Adric shows up, previously believed to have been killed, who warns that he will die again if Nyssa and Tegan continue onwards, and urges them to retreat. However, Nyssa outs Adric as a mere apparition upon noticing his star-shaped badge, which the Doctor destroyed when he lethally grinded it into the late Cyber-Leader's ventilation unit aboard the TARDIS. Knowing this, they press on, causing "Adric" to dissipate. Due to Nyssa's empathy, the two are able to enter the central chamber without obstruction. Nyssa, acting on instinct, throws an artifact into a large object in the chamber, causing a surge of power that disrupts Kalid's energy source, revealing him to be, to no-one's surprise except the Doctor's, the Master back again.
The Master explains that he barely escaped from their last encounter in Castrovalva, his TARDIS damaged in the journey. Now stuck in Earth's past, he seeks to use the power source in the central chamber to power his TARDIS and escape, and is using the passengers and crew of the Concorde to break into the chamber. The Master uses the Doctor's TARDIS to try to access the central chamber directly, while the Doctor, along with Hayter, find that the passengers have successfully broken through, and enter the chamber directly, rejoining with Nyssa and Tegan. They find that the energy source is really a gestalt intelligence of a great number of members of the Xeraphin species; their species were targeted in the crossfire between two other warring species, and they had tried to escape, but instead crashed to Earth, where the radiation of their damaged ship wracked their bodies, forcing them to take the form of a Hive Mind within the gestalt. They had constructed the Citadel to house the gestalt until the radiation had waned. However, when the Master arrived, his presence caused the gestalt to become unstable and causing a split personality within it, one evil side willing to help the Master, the other good side seeing his villainy and trying to stall the Master's actions.
The Master finds he is unable to access the central chamber with the TARDIS, and instead creates an induction loop to transfer the gestalt to his own TARDIS with the aid of the evil part of the gestalt. The Master attempts to leave but finds several parts of his TARDIS missing, taken earlier by Stapley and his crew, and though he replaces them with some from the Doctor's TARDIS, still lacks a critical temporal limiter. The Master offers a deal with the Doctor for a temporal limiter in exchange for the other parts he took and releasing the humans from his control. After installing the device, the Master departs in his TARDIS. The Doctor quickly instructs the humans to return to the second Concorde, and then uses his TARDIS to guide the aircraft back to contemporary times at Heathrow.
In the end, the Doctor explains that he had programmed the temporal limiter so that the Master's TARDIS arrived later than his, and materialised his TARDIS where the Master's TARDIS would appear. As they observe, the Master's TARDIS fails to materialise and is bounced to an alternate destination — modern-day Xeraphin, where he would likely face the wrath of that species. Then, thinking that he's finally gotten Tegan home at last, leaves her there — unaware that she was having second thoughts about the job and really wanted to stay aboard the TARDIS.
- Agent Scully: Professor Hayter, who thinks the entire thing is an elaborate Soviet hoax.
- Ascended to a Higher Plane of Existence: Professor Hayter, after obtaining the knowledge of the Xeraphin.
- Big Red Button: Discussed, sort of. When looking for the TARDIS door control, Captain Stapley immediately dismisses the HUGE RED LEVER, presumably for this reason.
- Chekhov's Skill: In what threatens to be the most barmy moment of Doctor Who (and this is a hotly-contested category), Tegan shepherds the dazed passengers across a swamp and back into the Concorde as though they are on the tarmac at Heathrow.
- Continuity Nod:
- The Doctor says that Adric died saving others, just like his brother.
- The Doctor activates a feature in the TARDIS to shift the interior of the ship so it is the right way up. Nyssa says that she wished that they knew about this feature back on "Castrovalva".
- The Doctor thought that the Master might have been destroyed when the illusory city of Castrovalva vanished.
- The Doctor says, when cold, it's "times like this I wish I still had my scarf."
- When Nyssa and Tegan try to reach the sanctum, images of Adric, the Melkur ("The Keeper of Traken") and a Terileptil ("The Visitation") appear in order to dissuade them from going on any further.
- Nyssa mentions that the Master killed her father Tremas.
- Cool Plane: The Concorde. And two of them to boot.
- Crystal Ball: Kalid has one.
- Danger Deadpan: Captain Stapley of Concorde Golf Victor Charlie shows remarkable self-control and British reserve given the circumstances.
- Dramatic Unmask: Literally the only reason why the Master is disguised as a Middle Eastern mystic in the Jurassic period. There is no-one with him, or even alive at this point in time, meaning it's entirely for the benefit of the audience at cliffhanger time. On the other hand, it does set up the hilarious piss-taking of the Master's Complexity Addiction in "The Mark of the Rani".
- Elmuh Fudd Syndwome: The Master's disguise gives him an unfortunate speech impediment that makes him hard to understand at times,
- Face Your Fears: Nyssa's personal illusion is seeing the Master's TARDIS again. "I don't believe in you!" she cries before stomping right through it like a B.A.M.F.
- Forgotten Fallen Friend: Adric. Aside from the opening discussion between the surviving members of the TARDIS crew, followed (in the next episode) by Tegan and Nyssa encountering a projection of him, his death is barely acknowledged within the story.
- Heroic Sacrifice: Hayter gives himself up to the Xeraphin so that the Doctor can communicate with them.
- Hive Mind: The Xeraphin.
- Just Plane Wrong: That control tower sure is understaffed.
- Lie to the Beholder: The Concorde crew thinks they've landed back at Heathrow, not in a Jurassic swamp. They don't even feel the plane shake when it touches down in a rough patch. One of the other jet's passengers thinks he's in Russia. A phony Adric tries to block Nyssa and Tegan's path, saying that if they pass through him, he'll vanish for good.
- Lighter and Softer: After the Gut Punch of Adric's death in the previous story, a lighter touch was used here. Despite the presence of the Master, no one dies onscreen other than Professor Hayter, and even he Ascended to a Higher Plane of Existence in compensation.
- Mass Hypnosis: The Concorde crew and passengers are hypnotised into believing they were at Heathrow Airport rather than the mid-Jurassic.
- Mass Teleportation: Happens to the passengers and crew of the Concorde.
- Offscreen Moment of Awesome: The massive Cyberman invasion fleet that was mentioned in the previous story is mentioned by Nyssa as having been dealt with off-screen. In fairness, the previous story did at least have the Cyber-Leader mention that their fleet wasn't strong enough to deal with Earth by itself, needing them to resort to their bomb plot to soften it up first.
- Put on a Bus: Tegan. She comes back with shorter hair next season.
- Significant Anagram: Kalid is credited in the first episode as Leon Ny Taiy — an ambiguously Asian anagram of Tony Ainley.
- Spanner in the Works: Stapley invokes this by name when he admits he swapped around some of the parts in the Master's TARDIS, hoping to disable it. He thinks it was a stupid idea, since he had no clue what he was doing, but it works nonetheless.
- Spot the Imposter: Phantom "Adric" is still wearing his badge.
- Stock Footage: A very blatant example when the Concorde takes off from the Jurassic - made worse by the fact it's behind model mountains.
- To Absent Friends: The brief (read: one minute and fifteen seconds long) discussion of Adric's death. Hopefully they did some more heartfelt mourning off-screen.
- Trailers Always Spoil: Averted among rare circumstances. Adric turns up here so as to allow him to be featured in the credits for the edition of Radio Times that came out on the day part three "Earthshock" was aired... and so concealed his death in part four.
- Undercover When Alone: Why the Master maintains his cover as Kalid, including the strange mystical chanting, when he is alone is anyone's guess.
- Unexplained Recovery: The last time we saw the Master, he was trapped in the mathematically-constructed city Castrovalva as it collapsed in on itself. The full "explanation" for this was as follows:The Doctor: So you escaped from Castrovalva. I should have guessed.
The Master: As gullible as ever, my dear Doctor.
- Wham Shot: As the TARDIS takes off at the end, the pilots see it off... as well as Tegan, who rushes into frame. This after it was assumed she'd want to be back home.