An invasion is underway on an oil rig. In the distant future, a race of beings encounters an impenetrable spaceship. The Master is planning to escape his top-security prison on Earth. These events are far more related than anyone realises.
Jo Grant, Brigadier Lethbridge-Stewart, Captain Yates, Sergeant Benton.
Pg 53 The TARDIS is in UNIT HQ at the beginning of the story.
Pg 164 On a beach at Durlston Heath, during Viking times.
Pgs 202/231 On board the Consolidator, billions of years in the future (page 201).
Pg 269 Praxilion, ten million years earlier.
Pg 348 Praxilion, millions of years earlier.
Pg 353 UNIT HQ, London, present day.
A familiarity with the conclusion of The Daemons would be helpful.
Pg 21 "Certainly the young woman pressing her face to the helicopter's window had not had much of a clue about what she was getting into when she was first assigned to UNIT. Time travellers, ancient enemies from beneath the Earth, forces and factors beyond the planet" The ancient enemies from beneath the Earth are likely the Silurians. But see Continuity Cock-Ups. The factors beyond the planet refers to Colony in Space, Jo's first adventure in the TARDIS.
Pg 24 "Oh - and by the way - that inane humming happens to be a rendition of one of the greatest tragic operas in the history of the Venusian arts." The Curse of Peladon, Venusian Lullaby.
Pg 25 "I used to know a MacCrimmon once - awfully decent fellow." Jamie MacCrimmon (The Highlanders et al).
Pg Pg 55 "Nothing that you or I have ever encountered fits the bill. And the fact the Daleks aren't involved may be the last piece of good news I have for you." This suggests the Brigadier has met the Daleks, setting the story after Day of the Daleks.
Pg 57 "I am known universally as the Master" Terror of the Autons.
Pg 64 "If it's not the Yeti, it's the Cybermen; if it's not them, it's the Autons or the flipping Silurians." The Web of Fear, The Invasion, Spearhead from Space, The Silurians. See Continuity Cock-Ups.
"And yet the Master and the Nestene Consciousness were working together to direct the Auton invasion" Terror of the Autons.
Pg 69 "Just a moment, Susan..." An Unearthly Child et al.
Pg 73 "But if a word of this gets out to him - or to anyone else in UNIT, or Geneva, or C19 - I'll need look no further than you for the source of the leak." C19 were mentioned in Time-Flight and featured heavily in The Scales of Injustice.
Pg 76 "Bessie, the Doctor's bright yellow Edwardian roadster, made an incongruous sight as it pulled up at the heavily defended checkpoint." Doctor Who and the Silurians et al.
Pg 116 "Where there was life there was hope, always and forever." One of theThird Doctor's common sayings (eg Monster of Peladon, Planet of the Spiders).
Pg 156 "What you are driving towards are alien creatures, no different from the Axons or Autons - you understand?" The Claws of Axos, Terror of the Autons.
Pg 161 "'Aye,' Irwin said. 'And the Clangers, they're real as well." The Sea Devils.
Pg 166 "The Doctor struggled with it for a few moments, then dug out his sonic screwdriver." Fury From the Deep et al.
Pg 174 "You can't do your usual bargaining with the enemy, Master. It may have worked with the Axons and the Nestene Consciousness, but they needed your cooperation." The Claws of Axos, Terror of the Autons.
Pg 194 "An Ogron would have tried counter-gravitic torque equalisation." Day of the Daleks.
Pg 195 "This was still not independent time travel of the kind the TARDIS used to be capable of, before the Time Lords banished the Doctor to Earth" The War Games, Spearhead from Space.
Pg 199 "Back before he had to bother himself with Yetis or Cybermen or strange men in blue boxes." The Web of Fear, The Invasion.
Pg 203 "The Sild time ruptures were beginning to cause local weather anomalies" Just like what happens in The Claws of Axos.
Pg 207 "Reminds me a little of Skaro..." The Daleks et al.
Pg 220 "It was no version of the Master that the Doctor recognised. A young man in a business suit, beardless, with a mop of boyish hair. His face, what the Doctor could see of it, seemed friendly and plausible. The face of a politician" This is the John Simm Master, aka Harold Saxon (Utopia, The Sound of Drums, et al).
Pg 223 "'My guess,' the Doctor said, 'is that the Sild have messed things up so thoroughly that all classes of time paradox are now possible. Even a type three Blinovitch crossover."' The Blinovitch Limitation Effect was first mentioned in Day of the Daleks.
Pg 231 "He had even seen the Earth itself incinerated, as as the enlarging sun spread its envelope nearly all the way to the orbit of Mars." The Ark.
Pg 235 "Time dams, of a particularly crude and inefficient variety." The Pirate Planet.
Pg 260 "Generally incarnations were prevented from meeting, but that was not to say it never happened. In times of crisis, in moments of great cosmic emergency, those appalling hypcrites on Gallifrey had been known to bend the odd rule or two." The Three Doctors.
Pg 303 "A large creature, such as an Ice Warrior or a Judoon, would never have fitted within." The Ice Warriors et al, Smith and Jones et al.
Pg 316 There's a thing like a cactus that's probably a Zolfa-Thuran (Meglos).
Pg 320 "Where there was life, there was yet hope." The Monster of Peladon, Planet of the Spiders.
Pg 336 "Your precious Blinovitch would be spinning in his grave, if he were anything other than a myth." Day of the Daleks et al.
"Back to a miserable prison cell, with only a colour television for company?" The Sea Devils.
OLD FRIENDS AND OLD ENEMIES
The Delgado Master.
Pg 220 The John Simm Master, the Peter Pratt Master, Missy.
NEW FRIENDS AND NEW ENEMIES
Edwina "Eddie"MacCrimmon, as well as several Praxilions.
Pg 35 The Sild. They are blobs in glass jars affixed to the back of metal crabs, who attach themselves to other species to possess them.
Pg 227 A robot, as big as a house, with a spherical body and a spehrical heads with talons, pistons and probes.
Pg 316 A towering, grey-frred thing with two red eyes in the middle of its sternum.
An alien made entirely from water.
Pg 44 A trawler.
Pg 257 We get a flashback to the Doctor and Master as friends on Gallifrey.
Pg 269 Praxilion, ten million years earlier before the previous setting.
Pg 313 Aberdeen.
Pg 349 Praxilion, millions of years earlier than the setting before.