Roots: Star Trek (a Scottish-accented Engineer), Aladdin ('Open Sesame!'), Star Wars ('You are our only hope...') The Prisoner ('I am not a label, I am not a number, I am a Monan!'). Morecambe and Wise (the Doctor's 'wrong body' joke).
The Doctor's line 'Life wins!' recalls its use by the eighth Doctor in Jonathan Blum and Kate Orman's BBC Book Vampire Science, while his mention of 'the Pink And Purple Polka-Dot Pyjamas Of Rassilon' come from a letter to DWM circa issue #83.
The Seriphean galaxy also features in the 'Dalek Empire' series of Big Finish audios.
Romana returned from E-Space and became President of Gallifrey in Terrance Dicks' Virgin New Adventure Blood Harvest (although no explicit links are made here).
Goofs: Assuming he is the same person, since 'The Sirens of Time' Raldeth's name seems to have changed to Reldath. If a solo Dalek couldn't remove Evelyn's eyes, why did it not just kill her and get Vansell to retrieve them? Whilst describing the cost of destruction of the Seriphean Galaxy, the Doctor expresses its area (i.e. distance not volume) in light years.
Fluffs: Colin Baker's faux-Latin pronunciation of 'imprimature'. ('The Two Doctors' was such a long time ago...)
Technobabble: Seemingly standard in SF nowadays, the Eye of Harmony has a 'flux comparitor'. Mention is also made of an 'epsilon reticular gauge'.
Double Entendres: 'For a slight girl Vorna, you pack quite a wallop'
'You must be shown 'The Power of the Daleks''
Dialogue Disasters: 'Resistance is Useless' (read the manual, Mr Cole...)
From an alien species, the phrases 'crazy', 'screwed up' and 'where the hell...' [a translation convention?]
'Ooh, aren't you an interesting colour?'
Dialogue Triumphs: 'Complacency - the middle name of most Time Lords'
'Is that space-minutes, or good old-fashioned Earth minutes?'
'Now I've seen everything: a Dalek silly mid-off'
The Doctor: 'Daleks... will I ever be rid of them?'
'Life from death - do you hear that Dalek? Life wins!'
Best of all, Romana: 'To travel again - to open a door and not know what lay on the other side!'
Continuity: The planet Archetryx is host to a 'Time Treaty' of 'twenty of the greatest powers in space-time', including the Time Lords but excluding the Dalek Empire. Among these races are the Virgoans (who have a reputation for selfishness, implied by Vansell) and the Monan Host, whose own achievements in some areas better Time Lord technology (though they haven't yet managed dimensional transcendence). Their time vessel is 'the most powerful ship at the conference' and resembles a grey box. Its engines are powerful enough to cause a slipstream of temporal disturbance themselves. It is implied that the Monans are allies of the Andromedans [ which would explain their rivalry with Gallifrey - see 'Trial of a Time Lord']. Archetryx is protected by a temporal barrier, inside which everything is one minute in the future. It also has Gravity Wells [subterranean shafts of zero gravity able to be manipulated]. Ettra Prime is the oldest planetoid in the known universe and contains particles of what the Daleks dub 'the Apocalypse Element', an entropic power present in crystals which can channel mental energy and behaves contrary to the laws of physics. Some of this mineral had previously been used by the Monans to enable time travel; essences from it can only be manipulated telekinetically and in zero gravity. Twenty years previously the Daleks removed Ettra Prime from space-time, enslaving those currently upon it (including some Monans and a Time Lord delegation led by then President Romanadvoratrelundar), and killing three hundred of the Time Lords with temporal distortion (it is not explained for what reason, or why the bodies were dumped on Archetryx).
Little is revealed of the [supposedly humanoid] Archetryxans, although they appear to be familiar with Earth vernacular (see 'Dialogue Disasters').
The Daleks here are led by the Black Dalek and refer to Skaro. Their brainwashed agents reply to commands verbally. Dalek mutants can exist outside their casing indefinitely in zero gravity (c.f. 'Resurrection of the Daleks' and other stories) and don't like strong light. Dalek ships can carry twenty or more Daleks at one time (their Task Forces comprise of thirty) and possess a form of 'chameleon circuit'.
Gallifrey's galaxy is a neighbour of the Seriphean Galaxy (or Galaxy 17A53), four times the size of the Milky Way galaxy and home to over six hundred billion stars. Vansell suggests that some citizens of the Capitol may have taken refuge 'in the North'. Much of Time Lord technology in the Citadel relies on Gallifreyan retinal technology (see: Links), but can be reprogrammed to include other races, such as humans (presumably Trinkett isn't technically human, another reason why she is allowed to remain on Gallifrey, as suggested at the end). TARDISes are kept in 'cradles' in their docking bay.
Neither the Doctor nor Romana care for Vansell. The Rod and Sash of Rassilon are both needed to manipulate the Eye of Harmony. The process necessary to open it would appear to be the same as in 'Doctor Who'. The Doctor's previous status of President has been revoked, along with his Presidential access codes. Romana's have not.
The incumbent Lord President (the same as in 'The Sirens of Time') greets the Doctor warmly, having come out of retirement to rule Gallifrey, Romana having been one of his successors. Romana disappeared mere weeks into her reign. It is not explained how she came to return from E-Space to Gallifrey, or what became of K-9.
At the end of the story Evelyn's retinal print is removed from the security matrix, but the Doctor advises her not to look too closely at the TARDIS, as he cannot be certain how it will react to a human retinal print in future (see 'Doctor Who').
Links: 'The Sirens of Time', 'Doctor Who' (retinal technology), 'The Invasion of Time', 'The Deadly Assassin', 'Destiny of the Daleks' ('seek, locate, exterminate'), 'The Daleks' (Evelyn's legs are paralysed by Dalek weaponry) 'The Dalek Invasion of Earth' (the Daleks hollow out a planet to use as a vehicle) 'The Spectre of Lanyon Moor' (Creating feedback loops is, apparently, Evelyn's specialty), 'The Five Doctors' and 'The Trial of a Time Lord' (the Doctor's presidency), 'Warriors' Gate' (the Doctor refers to Romana being in E-Space).
Untelevised Adventures: Evelyn's malapropism of The Stockholm Syndrome recalls the village of Stockbridge in Doctor Who Magazine's comic strips (did they recently visit?).
Location: The planets Archetryx and Ettra Prime, Gallifrey (including the Presidential Chamber, the TARDIS cradles and the Eye of Harmony beneath the Panopticon), c4162 (see below)
The Bottom Line: 'Welcome back, Romana'. The culmination of one of the most popular fan fantasies, 'Apocalypse' finally stages an all-out Dalek attack on Gallifrey, and very nearly has the forces of evil win. There's an awful lot going on here, and the story could perhaps have been an extra episode longer, but it's all handled competently, with only a few battles defying visualisation. Romana's return is marked with an older, wearier companion reappearing to take over her future role with confidence. The Daleks continue to be pure undiluted evil. While not quite as epic as it would like to be, it's frightening to think how badly it all could have turned out but didn't.
Romana's return to Gallifrey and her ascendency to President of the High Council is complicated. Some time after The Five Doctors (the nearest story to the beginning of the presidency of then-Chancellor Flavia) we can assume Romana returns from E-Space with K9. 'Invited' by the High Council to challenge Flavia's successor (implied to have been part of a coup which overthrew her unremarkable term) she successfully defeats him, assuming the Presidential title - the Doctor becoming aware of this in The Chaos Pool. Soon afterwards, she is captured during a diplomatic mission and imprisoned by the Daleks for twenty years, during which time we might assume the Sixth Doctor is summoned for his trial by a corrupt High Council regime and, following its collapse, an un-named interim President is instated (The Trial of a Time Lord.) Though the Sixth Doctor declaims a post-Trial President as evidence of further High Council rigging (The Wrong Doctors), conceivably this could be the same Lord President who features in Sirens of Time and is usually inferred to be the same individual killed in The Apocalypse Element. At the conclusion of Apocalypse Romana returns to Gallifrey once more and is reinstated, her presidency continuing through the Eighth Doctor's life (Big Finish's Shada, Neverland, Zagreus) and, after the turmoil of the first three Gallifrey series, ending with her deposal and replacement by, initially, Braxiatel, and later President Matthais (Gallifrey: Mindbomb.) What follows is, according to the Gallifrey series, a period of certain chaos and the possible fall of Gallifrey, although the series in following Romana's escape from the planet to an alternative reality effectively dodges the question of the collapse's larger events and of the fate of Romana's successor. Perhaps it is under Matthias that a struggling Gallifrey faces the return of Morbius (Sisters of the Flame/The Vengeance of Morbius) and the actions of 'X' (Dark Eyes) through to the beginnings of the Time War; the identity of the President and Lord President in respective stories is unknown and inconclusive.