Roots: Professor Bernice Summerfield appears courtesy of Virgin Books' 'New Adventures', first appearing in Cornell's Love and War and more recently, Big Finish's audio and novel series based around her (see box below). Vincent Ward's original screenplay for Alien3, plus Aliens ('Game over, Bernice'). Biblical and Christian versions of inner demons (666, pentagrams, the Scourge speak of being 'exorcised'). Genesis' 'Home by the Sea' ('things that make up a life'). The Scourge as praying mantises may be based on the M.C. Escher etching 'Dream'.
Intertextuality: The character of Bernice Summerfield was conceived originally for Virgin Books' New Adventures series, but since her separation from the Doctor in that range and continuing adventures in both the Virgin books and for Big Finish, early claims of her 'in-Who' audio adventures as being a 'side-step' from the Doctor Who audios appear to have been largely overwritten.
Whilst in the Doctor's mind Benny says that Ace told her she too had once been there, a reference to Paul Cornell's debut New Adventure Timewyrm: Revelation
Ace's uniform and Spacefleet memories come from a time between her leaving the Doctor at the end of the New Adventure Love and War and her uneasy return to the TARDIS in Peter Darvill-Evans' Deceit, during which she was a trooper against the scattered Dalek species.
Goofs: Why do the Scourge need surrender papers before they can invade Earth? [either the Doctor has convinced them they do or perhaps this is an extension of the tradition of demons having to be invited into a dwelling or world]
A Scourge soldier searches the basement of the hotel whilst Ace, Benny and Michael are hiding - why doesn't it hear the deaf Ace shouting?
Gary says he placed Bernice in a staff bedroom, locked the door and pushed the key card under it, yet after she wakes she merely crosses the room and opens the door.
Technobabble: Besides Dr Mike Pembroke's temporal accelerator, we have a 'fractional universe' created by the Scourge. Mary Hughes is burned from the inside out by 'hard radiation' generated by its quantum adjustments.
Double Entendres: Many, many single entendres courtesy of Ms Summerfield. Pembroke's machine 'works with theoretical particles beneath the quantum levels of reality... by finding holes in the plot of the Universe'
Fashion Victims: Ace's glossy black Spacefleet uniform gets a lot of attention from Mike.
Dialogue Disasters: 'We tire of this dance, meat puppets'
'Pitiful humans. Who can save you now?' (As it happens, he does)
Dialogue Triumphs: 'Run. Cry out. We are the Scourge, and we will devour you'
'We are human failure. We live in the gap between what you are and what you could be'.
'I'm the Doctor, I always win... I'm the one the monsters are afraid of. So tell me - are you getting scared yet?'
Continuity: The Scourge is a race of insectoid aliens occupying a universe on a higher dimensional plane. They have preyed for 'millennia' on the despair, and terror of lesser beings, including humans and possibly Time Lords [they seem convinced that they need Time Lord consent to take over Earth, suggesting that they are wary of them, yet the Doctor is vulnerable to them, perhaps due to his half human parentage]. Essentially they are the inner demons within all humans, and if successfully established on earth, would have immense powers, walking around time, reaching through walls and entering human thoughts. Their army includes a leader, a demi-leader and a bridgehead. They claim their victims by way of a pentagram shaped 'burn' or 'scar' on the victim's right palm which can be passed by touch - victims later transform into Scourge hybrids. Their voice operates on a level that inspires religious awe in humans (meaning that they can command anyone who hears them at will) - if they were successful in their invasion humanity would have no choice but to worship them. They can detect temporal [artron?] energy.
The Doctor books room number 666, under the name of Summerfield. Perceived by the Scourge bridgehead, his 'shadow' stretches back and forth across time. He discovered the Scourge earlier whilst dreaming on the astral plane (c.f. 'Doctor Who and the Ghosts of N-Space'). During Mike Pembroke's time experiment he experiences a moment of dizziness. As his body is attacked by the Scourge shadow, he falls into a self induced coma (c.f. 'Planet of the Daleks', 'Planet of the Spiders' and other stories). The inside of his mind (as experienced by Bernice) is a vast, echoing space complete with tasteful furniture. There she glimpses embodiments of the Doctor's other selves, including his eighth persona, whom the Doctor assures her is at this stage merely a possibility and no guarantee of his survival (this might suggest that all of his potential incarnations reside there, or at least one of each of his 'lives').
Ace carries a tool issued by Spacefleet and used for prying the tops off Daleks casings - she uses it to open the hotel lift doors. She is deafened in this story, and is confident that the TARDIS Medical Bay can fix this. Being made deaf by having her ears boxed is the most painful thing she's ever had to endure - and is the bravest thing Benny has witnessed.
Bernice had two turtles once whilst living in isolation - they died when the men she was fleeing came to arrest her. She asks Annie if her (fictional) spirit from Rigel IV knows 'Johnny Clarke - the guy who reads the weather on the nightly news'. Like Squidgy and Slimy, she may have made this up.
The TARDIS medical bay has nanites enabling the reconstruction of body tissue. The Doctor diverts them to the Console Room.
Links: Love and War (Bernice recalls that when she and the Doctor first met, he asked her to have faith in him)
Untelevised Adventures: Several months ago in the Doctor's timeline the Time Lord visited a guest house where Michael Pembroke was staying and adjusted the settings of his machine.
In one of his incarnations the Doctor picked a flower and sniffed it comedically to cheer up a companion whilst visiting a small English village (the memory of its smell is lost forever in this story).
The Doctor suggests he'll revisit Brian Hughes in ten years' time (though he might not...)
Future History: The pacifying gas 'Pacificus' is developed sometime in the 21st century. Ace tells Mike that time travel technology is discovered by humans 'later'.
Location: The Pinehill Crest Hotel, Newmansgate, Kent on the 15th of August 2003.
The Bottom Line: 'Fear prevents us from doing anything, but love stops the fear'
'The Shadow of the Scourge' is far less an audio episode than a New Adventure with sound effects. Ace is clearly a different model, and Benny is the character her creator intended her to be. The Doctor at a late stage admits he's making it up as he goes along and has no knowledge of what becomes of Brian Hughes, merely having faith that things will turn out for the best. Everyone involved in the story is so advanced from their televised personae that this 'side step' can only be just that - a bold, frantic flight from so many conventions of the television series. With cracking dialogue, some gruesome set pieces and real emotion at its core, 'Scourge' is an accomplished realisation, despite the suspicious central notion of human dismay being an alien fabrication.