Roots: The scenes in Hell are reminiscent of the Hellraiser films. There are references to Beethoven's Fifth, Houdini, Oscar Wilde, Doctor Jekyll and Mister Hyde, Dickens, Shakespeare, Alice in Wonderland, Botticelli, Edgar Allen Poe's The Fall of the Rise of Usher, Disneyland, Darwin, Lyall, Scott of the Antarctic, Sir John Franklin, Absolutely Fabulous, Peter Pan, Hamlet, Achy Breaky Heart, Herodotus, The 1001 Nights, Bachs Toccata and Fugue in D Minor, Jules Verne, Wile E. Coyote, Road Runner, Bugs Bunny, Daffy Duck, The Chipmunks, Vincent Price, Newton, The Hound of the Baskervilles, Prometheus, Sisyphus, Tom Thumb, Tenniel, Lewis Carroll, and Brer Rabbit. There are quotations from the hymn And Did These Feet in Ancient Times and Bob Dylan's All Along the Watchtower.
Dialogue Disasters: The Doctor and Sabbath utter occasional uncharacteristic Americanisms, presumably due to Lloyd's nationality, the most grating of which is Sabbath's use of the word quit.
Dialogue Triumphs: 'Ideas that threaten the centre are always pushed to the edge. The truth is forced to keep company with the silly and the rightfully scorned.'
'I am, in fact, quite intelligent.'
The Doctor's entire lengthy philosophical discussion with Sabbath, but especially: 'Injustice is the rule, but I want justice. Suffering is the rule, but I want to end it. Despair accords with reality, but I insist on hope. I don't accept it because it is unacceptable.'
Continuity: The Doctor calls Sabbath Time's Champion [a nod to the New Adventures, especially Love and War]. Sabbath's motivations are explained to a degree; he is opposed to chaos and believes that unauthorised time travel creates parallel universes, threatening the fabric of reality (The Doctor disagrees, but Sabbath doesn't believe him). Sabbath's alarms and defences are keyed to his biodata. The Doctor confirms to Anji and Fitz that his heart gives Sabbath some of the physical advantages that were bred into his people over millennia of time travel [the symbiotic nuclei and the Rassilon Imprimatur - see The Two Doctors]. He once told Fitz that he wears his big coat in a spirit of irony. He adopts the alias G. K. Thursday, retried clergyman and amateur student of the fauna of Dartmoor. Following the death of his new companion, The Angel-Maker, he tears the Doctor's heart out of his chest in disgust [presumably, he has had it long enough to retain the Rassilon Imprimatur (The Two Doctors)]. The Doctor places it in a jar and donates it to the carnival.
The Doctor has been having panic attacks brought on by the sound of his single pulse. The unfamiliar pulse stopped him from being able to sleep for a while afterwards. Since the loss of his heart, he is colder all the time, especially his extremities. In a nod to his past incarnations, he has a vague feeling that he used to be shorter, but also that he used to be taller. He dislikes Sabbath, resenting the fact that Sabbath saved his life and then played him for a fool on two separate occasions (Anachrophobia, History 101). The Doctor discovers that Sabbath implanted the Doctor's second heart into himself, to his fury. This creates a biodata link between them which means that the Doctor cannot die whilst his other heart beats in Sabbath's chest. He discovers this after being seriously injured, his chest crushed and ribs puncturing his remaining heart. The Doctor takes advantage of this fact to use a mortal wound to visit Death, knowing that Sabbath will have no choice but to rescue him [this seems to be Death the Eternal as seen in several New Adventures, including Love and War, although she doesn't seem to recognise the Doctor]. The biodata link also allows the Doctor to surf into Sabbath's mind and thus communicate telepathically with him, to Sabbath's disgruntlement. The Doctor again uses the alias Doctor John Smith. He has studied Charcot's work on hypnotism and hysteria. He rents a two-bedroom flat with a box room in London for himself and his companions. He places a whoopee cushion on Sabbath's seat. He knows that time travel used to be restricted, but can't remember by whom (see The Ancestor Cell). He knows a lot about carnival life (presumably from his time spent on Earth during the twentieth century). He bakes a Lady Baltimore cake. He is claustrophobic, but feels that he shouldn't be, which worries him. His pupil response is different from that of a human. Whilst in the time machine, he sees his past incarnations, but doesn't understand the significance of this (although he recognises the Seventh Doctor from his dream in The City of the Dead). After Sabbath gives up the Doctor's second heart, he starts to grow a new one.
Fitz dons an uncomfortable three-piece suit and stiff collar. Both he and the Doctor wear soft, wide-brimmed hats. He has always been vaguely interested in fossils. He turned thirty-three in Guernica (History 101). He feels uncomfortable in Chiltern's asylum, due to memories of his Mother (The Taint).
In order to blend in with the times, Anji reluctantly dons a sari. She later changes into jeans, a cap, and one of Fitz's spare coats. She watches archival reruns of Absolutely Fabulous in the TARDIS. She drinks Scotch.
The Doctor uses the TARDIS time sensors to scan England for temporal disturbances, and also performs a biological scan to cross-reference with. The Doctor sets up an exclusionary field keyed to Sabbath's biodata in the TARDIS to stop him entering.
Time travel using mirrors is called temporal interferometry. The Doctor knows that he has encountered it before, but can't remember where (The Evil of the Daleks, Time of the Daleks). It is not explained who built the time machine seen here, which works on a system of eight mirrors. Improper use of the machine splits human uses into eight separate, linked, individual fragments. Unable to cope with the Doctor's unique temporal attributes, it disintegrates when Chiltern forces him into it.
Links: Unnatural History (biodata, and Fitz refers to San Francisco), The Adventuress of Henrietta Street (the Doctor's heart). The Doctor mentions his discussion with Sabbath in Spain (History 101). There is a reference to the Doctor waking up on the train between the end of The Ancestor Cell and the start of The Burning. Fitz refers to the Clock-faced People (Anachrophobia), the Onihr (Trading Futures), and the cartoon planet (The Crooked World). The Doctor has a vague and uncomfortable recollection of making a deal with a moral monster before, connected to a fear of falling, which is a reference to his alliance with the Master in Logopolis and subsequent regeneration. The Doctor asks Chiltern if he expects to find the mind-brain interface just sitting in his brain, with a little sign pointing to it, which is a joke reference to The Invisible Enemy.
Location: Liverpool, Newcastle, Dartmoor and Wales, in July and August sometime during the late nineteenth century.
The Bottom Line: Dedicated to Paul Cornell, and with references to Time's Champion, Death, and owls, Camera Obscura feels very much like a New Adventure, which is one of its many strengths. The relationship between Sabbath and the Doctor is explored properly for the first time, and it is very satisfying to finally see the Doctor running rings around his manipulative opponent. A masterpiece, and one of the best EDAs in an already consistently excellent run.