Roots: Greek Mythology (Lethe), Mel (presumably) names the Juggernauts after Sooty, Sweep and Soo from The Sooty Show. It is likely the name 'Savo' came from an earlier anagram of Davros, and the 'Dr' became 'Professor' to make the word play less obvious (it's not that far removed from Dust Breeding's 'Mr Seta'). 1984 (Mel mentions George Orwell and Big Brother), Snow White and the Seven Dwarfs ("seven diminutive gentlemen whistling jaunty tunes whilst they labour"). The Doctor paraphrases from Richard III ("my kingdom for a map") and Congreve's The Mourning Bride ("hell hath no fury like a Mel Bush scorned!") Mel's antique music box plays Schubert's Ave Maria.
Intertextuality: The 'trademarking' of the name Juggernaut may be a dig at the licensing of the Dalek name by the Nation Estate. Mel's home address (35 Downview Crescent) in Pease Pottage was first given in Gary Russell's BBC Book Business Unusual.
Dialogue Triumphs: "A transmat dais, eh? How chic. And where pray tell will I be transmatting to?"
"-A subterranean cavern" "Well, that makes a change".
"Don't forget to write!"
"Thankyou, disembodied computer voice!"
"Fate has cast its dice for you, and the dots are in the shape of little Daleks."
Continuity: The planet Lethe is home to a domed mining colony owned by the Outreach Corporation. It has a methane-rich atmosphere and is prone to very strong wind gusts of up to 200 miles per hour; where water is rationed and the colonists have subcutaneous implants to monitor their movement and well-being.
The self-sufficient, self-repairing, and, [potentially] self-replicating Juggernauts are remodelled Mechanoids, reprogrammed for rudimentary tasks after having been recovered from mine shafts within Lethe (presumably dumped or left there by a previous Earth expedition, but well before the current generation are aware of them). Davros has adjusted them further, creating cyborgs from dead personnel - the central hub of the Juggernaut unit contains a cerebral cortex suspended in plasma, a heart and crude circulatory system. The Doctor surmises that, as some organs were retrieved before the unearthing of the Mechanoids, Davros intended to use them in more Daleks, as he had on Nekros.
The 'grey' Daleks here report to a Black Dalek and have 'time scoop' as well as transmat technology.
En route to his intended trial after capture on Nekros, Davros' prison ship was attacked and crashed on Lethe 716 days ago - Davros was in a coma for seventeen of those days. Davros' crashed vessel contained an escort of fifteen Imperial Daleks, three of whom survived, but in poor condition. Davros has given himself a metal prosthesis for a hand and his motorised 'skirt' is salvaged from one of his white Daleks casings. It contains a self-destruct mechanism.
Over two months pass between the time of Mel's and the Doctor's separation. Mel hasn't heard of Daleks or Davros. She is skilled in BASIC, Cobol and Fortran. She doesn't really believe in fate and suggests that she has been away from Earth for some time - the flat interior of the TARDIS is beginning to bore her.
The Doctor is accomplished in dancing the soft shoe and the Metabalean Oodleskip (or so he says) The Doctor can measure distances via sound reverberation - he demonstrates this in the dark listening for the echo of his raised voice; his sense of smell can detect the presence of oxygen, argon and methane in the air, as well as 'teratron', which is used in molecular disintegration chambers.
Future History: Earth has passed laws regarding mandatory organ donation. Geoff mentions something called "the Kensington Disaster of '97", in which his parents were killed.
Future stimulants include oxyproxylon and pentathlium.
Untelevised Adventures: The doomed medical ship the Doctor and Mel were on board prior to (and leading into) this story was piloted by a Captain Nazeel, a female non-human (not that Mel could tell her gender), possibly with some form of yellow appendages.
The Doctor says he knew Melvin Schwartz, Nobel laureate and co-discovered of the muon neutrino.
Links: The Chase, Genesis of the Daleks, Revelation of the Daleks, As the Doctor awakens on the Dalek spaceship, he first calls out for Evelyn. It is implied that Davros' mutilated condition at the close of this story leads him to take the form of Dalek Emperor in Remembrance of the Daleks.
Qv: 'Davros in Time'.
Location: The mining colony Lethe, a fringe planet in the Beta Orianus system. The events follow a short time after those of Revelation of the Daleks, although mention of 'Space Security law' could also place it around the time of the Dalek Masterplan.
The Bottom Line: We're hoping to use the retro design as a selling point. A nod to the past."
Terry Molloy's in-series swansong as Davros is a hugely traditional piece, sitting comfortably between Revelation and Remembrance while giving Mel the Dalek story she never had on screen. There's nothing new here - even the titular robots are Sixties discards. Diverting and reliable, and as well made as usual.