Roots: Many SF clichés abound, including an alien in the hold and a homicidal computer (Alien, also 2001: A Space Odyssey). As this is a Saward story however, the main influences come from ex-Doctor Who script editors Douglas Adams (bubbly ship's computer, servile robot - compare 'Barton' to 'Marvin', space police and GBH by bad poetry, all culminating in a Captain in a bathtub) and Robert Holmes (Saward's take on the comedic double act in Seedle and Snatch); pantomime, particularly Aladdin ('Open!' '-sesame?', 'your wish is my command'). The stock music from episode 3 is Philippe Entremont's arrangement of 'Satie: Gymnopedie No. 1' from the LP Bourneville Selection.
Goofs: As the TARDIS materialises on the ship, the sound of something dropping can be heard. After having fallen 12 metres, how is landing on Snatch supposed to save Peri's life and not end Snatch's? When sped up, the Maston's roars are a sound man saying 'Argh!'. Grant recognises the Doctor by his fair hair and not his overly conspicuous attire (surely an art thief shouldn't be colour blind or lack an eye for detail?). In episode 5 just after the Doctor says 'That's right', someone can be heard laughing. Most obviously, the story's conclusion conflicts with that of 'Terminus' (or possibly not - see below).
Technobabble: The secure door Grant hides his loot behind is made of Estidian steel, 'not even a Bastic torpedo would scratch it'.
Dialogue Disasters: 'Look at my pustules grow!'
'You're only programmed to sound like a dizzy dame, not act like one!'
'It's always significant if you find insignificance significant.'
'Frisk him, Snatch!'
Anything said in the Computer's public voice.
Dialogue Triumphs: 'You have the right to remain silent, but I wouldn't encourage you to do so. Anything you say will be taken down, altered to my satisfaction and used in a court of law to send you down for a good many years. So start confessing.'
Double Entendres: Snatch.
'This is no time to play the fool'
'I'm afraid sir, the only position I can adopt is a horizontal one.'
'Big, isn't it?'
Peri's single entendre on the TARDIS time spillage warning signal: 'It started to wink and flash and grunt like some dirty old man in a park.'
'Don't you think your gun's a little small?'
'I came as soon as I could.'
'I only hope it doesn't prove an anti-climax.'
The Doctor on drinking: 'I am a little naïve when it comes to this sort of thing.'
'Your pleasure is my pleasure.'
'Your gratuitous use of violence often disturbs me, lad.'
'Shut it off. I find it offensive.'
Continuity: In the TARDIS, the Doctor is contacted telepathically in his sleep. The TARDIS console winks and flashes and makes a 'grunting' noise to alert him of local time spillage [is this connected to the Cloister Bell?]. Upon materialisation, the TARDIS sound is slightly different - incorporating 'chirps' in its usual noises [a side effect of the time ripple]. The Vipod Mor is a census ship, having now made a galactic survey of all the known inhabited worlds for 'many years' [possibly connected with the Census organised by Galactic Centre (see 'The Happiness Patrol'), thus placing this story in the late 24th Century]. Among its crew are anthropologists and geologists - half of the crew are carbon-based life forms [it is possible this may not include the Captain]. The ship is gigantic - so large that Peri is unable to zoom the TARDIS scanner out far enough to capture its entire image. It has a gym and ventilation shafts twelve metres deep and the Doctor speculates that it might be possible to materialise the TARDIS inside the ship's computer. Aboard the ship and at large is a male Maston, a creature indigenous to Sentimenous Virgo, which was destroyed 'over a million years ago'. It is hairy, has eyes and a tail and is carnivorous. The Doctor has been drinking to excess and suffers a hangover, albeit briefly (c.f. 'The Twin Dilemma'), after three bottles of voxnic. Captain Slarn takes lava baths when ill and is able to cultivate diseases [including viruses] upon his body at will, even mors immedicabilis - 'the incurable death', to which even he is susceptible.
The ship's Computer has a programmed individual 'female' personality and an 'inner spirit', created by accident from a technician's oversight - 'a simple matter of crossed wires'. It is able to detect individuals by Infra-Red (fire warning) sensors and weight distribution (although the police device foils it and it initially perceives Peri as a 'Migarian Midget']. Its inner spirit is capable of thought transference and sends out a 'time ripple' to lure a Time Lord in order to the collect the contents [i.e.: the knowledge of temporal physics] of their mind to complete its own understanding of time travel. This would suggest that at this stage the Time Lords are known to human society. The Computer's inner self intends to travel back in time to the creation of the Galaxy before life existed and to influence evolution to reprogram away all aggression from life. Once the Vipod Mor is in temporal travel the 'public voice' of the computer makes a mistake with the co-ordinates, causing the ship to slip back (hence the title) to the creation of the Universe, which, at this time, is a 'mono-block of condensed matter'. The 'public voice' activates the self-destruct [it is 'the first computer to commit suicide'] and the ship explodes at the heart of the mono-block, triggering the Big Bang.
Peri claims that the Doctor never lies, and has told her that his real name is unpronounceable [c.f. 'The Trial of a Time Lord' episode 1]. Perhaps this is only to humans. Or Peri. Time experiments are illegal [a Gallifreyan law enforced by Time Lord agents?]. Shellingbone Grant is an art thief, using the Vipod Mor as a cover and hideaway whilst stealing famous art treasures from throughout the galaxy. At the end of the story a member of the High Council of Time Lords intervenes [it is not explained how, as everyone can hear him, and so it might not be telepathic as in 'The Hand of Fear' or 'The Five Doctors', his voice is deepened like Rassilon's in 'The Five Doctors Special Edition' - perhaps he is a hologram?].
Saward reuses some lines from two of his previous stories: 'You're destroying my mind!' ('Resurrection of the Daleks'), and 'On this ship we...' ('Earthshock').
Location: The Vipod Mor, deep space (see Continuity).
Future History: Mention is made of 'ancient Earth music' - either 'music from ancient Earth', or 'ancient music from Earth' [probably the latter]. As most of the crew is human, it could be inferred that this story is set in a time when human colonies are located throughout the galaxy (see above).
Untelevised Adventures: The TARDIS has just visited Zaurak Minor, where after asking for directions (to an unspecified location), the Doctor got drunk in 'a small drinking establishment'. At the story's conclusion he vows to visit 'the largest library [he knows]' - though this may be a joke. Presumably the Doctor and Peri drop Grant off at the same time, or turn him in - although the lack of evidence against him might prove difficult.
Q.v. The TARDIS Scanner.
The Bottom Line: 'I think I need to read up on my history.' The first of the radio plays, 'Slipback' is famous mainly for its noticeable similarity and subsequent clash with 'Terminus' and its Big Bang creation idea, made even more blatant by Eric Saward's presence during the latter's scripting and production. Besides this though, no other continuity is breached and thus far this play is the most faithful of the three to its era. All the Sawardian elements are here, usually for the worse, and the script doesn't appear to take itself too seriously, if at all. Colin Baker is great though, despite such an irritating supporting cast, although it's a shame to hear obvious violence and dwelling on Snatch's death. This is the second Eric Saward story in which a character with the name Bates is killed horribly.
BIG BANG VERSUS EVENT ONE
The Doctor is present, or close to the creation of various parts of the Universe at some points in his lifetime. In 'The Edge of Destruction' the TARDIS is taken back via its Fast Return switch to the creation of a solar system.
Taking the various references into a likely chronological order of occurrence: at 'the dawn of time' there exist only two forces, Good and Evil ('The Curse of Fenric'). The Terminus, a craft travelling from another universe, jettisons its fuel tanks after an accident into the void where the forces exist; potentially it is the explosion of the Vipod Mor (which is travelling backwards in time from the future which ignites the jettisoned fuel. The explosion causes the Good and Evil forces to shatter until only echoes remain. The Doctor likely witnesses all of this happen (in 'Destiny of the Daleks' he says that Oolon Colluphid's book The Origins of the Universe 'got it wrong on the first line. Why didn't he ask someone who saw it happen?'). A side effect of the explosion is an in-rush of hydrogen, in which the TARDIS becomes caught due to the Master's sabotage using Adric in 'Castrovalva'.
It is clear from the dialogue that Event One in 'Castrovalva' is supposed to be the creation of a [Earth's?] galaxy. The Doctor confirms in 'Four to Doomsday' that 'the Big Bang' relates to the origin of the Universe. But the Doctor later uses the term 'Event One' in 'Terminus' to describe the Big Bang. This is either a total contradiction of 'Castrovalva', or we might infer that Adric [and by association the Master?] is hopeless at astrophysics as he is the one who programmed the TARDIS data bank to impart the information about the Hydrogen Inrush in the first place.