Roots: Alien: Resurrection, The Doctor quotes Petter Dass. The Bible (Lazarus). Bugs Bunny cartoons ('wabbit season'). Greek mythology (Artemis, Hades protocol). The Doctor quotes Sir Arthur Conan Doyle. The Lost World: Jurassic Park (site B). Norwegian's A-ha's Morten Harket. The Forge resembles the Initiative from Buffy The Vampire Slayer.
Goofs: Nimrod refers to the Milky Way as Mutter's Spiral, when this is ostensibly a Time Lord term for the galaxy.
Fluffs: 'For King and Country' sounds a bit dodgy on delivery...
Dialogue Disasters: 'I thought wabbit season was months away!'
Dialogue Triumphs: 'Sounds like a night down at the student union'.
'I'm glad somebody's in awe of me.'
'Just doing my skull-duggery.'
'I was quite pleased with myself, but I usually am.'
Double Entendres: 'Ten seconds - that was quick.'
'I'm trying harder these days.'
'Fans tend to restrict themselves to a signed photograph.'
Continuity: Huldrans exude a blue slime which can stun, paralyse, or kill in relative quantities. They are small, thin and blue-skinned, and their speech resembles singing. They are also telepathic. They use swords, and travel through the vortex via a portal.
The Forge is run by the advanced Oracle computer. It's located underground in Dartmoor near Lynch Tor, and used to be in the nearby abandoned asylum. It contains a significant archive of alien species in cryogenic storage, as well as samples of Axonite and Zanium. Oracle can automatically initiate the Hades protocol to sterilise the facility if there is a containment breach. The Forge has a Beta site.
Nimrod is deputy director of the Forge. He used the Internet to track down Cassie and recruited her to the cause.
The TARDIS kitchen fridge automatically restocks itself. All TARDISes from Type Zero onwards have certain systems installed by the decree of Rassilon. One of these systems can track vampires by their blood. Time Lord telepathic contact can be registered as an energy disruption. Clones of Time Lords don't retain the ability to regenerate.
The sixth Doctor stopped amazing himself "two centuries ago" as he tells Evelyn. He has four sugars in his tea and his vegetarianism ('The Two Doctors') is obviously currently lapsed as Evelyn cooks him bacon. He can mimic voices (much like the Master in 'The Time Monster'). [Although to be pedantic, it was the clone that was the mimic!] He is wearing a coat different to that he wore in 'Project Twilight' [presumably the new blue one from 'Real Time']. The stress of losing an arm should be enough to trigger a regeneration. Government files on the Doctor include the term 'regeneration'.
Evelyn takes pills for her heart condition. She had had a mild heart attack before she met the Doctor. The University was going to retire her because of this. She never forgave the Doctor for Cassie's death, even "at the end".
The seventh Doctor is travelling alone, and considers going home. The console room is presumably that as seen in the TV Movie. He quotes from Hound of the Baskervilles. He claims to be less forgiving than his previous self. He doesn't forget faces but he does forget names.
Links: Project: Twilight, The Claws of Axos (Axonite), The Twin Dilemma (Zanium), Remembrance of the Daleks ('Shoreditch, London, 1963'), Battlefield ('Carbury, 1997'), The Wheel in Space (Time Vector Generator), The Three Doctors ('Contact'), The Deadly Assassin (Mutters Spiral), State of Decay, A Death in the Family.
Location: Five years after 'Project: Twilight', South Norway (18 July, and November, 2004); The Forge, Dartmoor, England, and four years later.
Untelevised Adventures: The Doctor once spent a debauched evening with Petter Dass. The Doctor once took piano lessons from Elton [presumably Elton John].
The Bottom Line: 'Welcome to the Forge.'
On the heels of Creatures of Beauty comes another experiment in story telling. The first half does rely on knowing 'Project: Twilight' well, in particular the details of Cassie and her life, without which it makes what happens to her have much less impact. The nature of the sixth Doctor in the latter half of the story is perhaps a tad too obvious, but the verbal duelling between the Sixth and Seventh Doctors is always fun to hear. Good to hear some old voices again - Nimrod makes for an effective villain.