Roots: The Tempest (the title is a quotation from Act I scene ii of Shakespeare's play), Flint paraphrases Nietzsche ("That which does not kill me makes me stronger"), the Doctor quotes from the film of Get Shorty ("You don't know me. You only think you do"), Marvel's Captain America (super-soldier experiments), Alien: Resurrection (failed cloning experiments), The X Files (amphibious super-soldiers).
Fluffs: The Doctor claims "Lee took it to be dilidium."
Goofs: Hoskings says there isn't enough fuel to return Ruth to the surface. He's probably lying, but why couldn't they refuel once they got to the surface? [Because they would draw too much attention.]
Dialogue Triumphs: "Smith. Doctor John Smith. But everyone calls me the Doctor. I've come to save the day."
"Time has no meaning when the sun no longer rises above you."
Continuity: What if...the ends really did justify the means?
The D.E.E.P (Deep-sea Energy Exploration Project) was a sub-marine science base, ostensibly funded by the military for Vollmer's research into black smokers, but secretly was for Lee's research into accelerated human clones and combining human DNA with marine predators to create 'super soldiers' (outlawed by a 'dozen' international treaties).
It existed up until the year 2039, whereupon it was allegedly destroyed by dirty bombs, sealing the base in a radioactive area of seafloor and ringed by high temperature geothermal vents. This poisoned the fish in a wide radius and affected fishing businesses. It currently has around 'a dozen' military quarantines preventing further access.
Ruth's father Professor Eric Vollmer conducted renewable energy studies at the D.E.E.P, apparently neglecting his daughter in his obsession with the nearby vents. He wanted to call Ruth 'Miranda' after the character from 'The Tempest' (with which he appeared to have some unaccountable obsession).
Through a mutual colleague 'Hanson', the Doctor was alerted to Vollmer's experiments and eventually the true nature of the base itself - he botched its initial destruction. The Doctor has a TARDIS (though it's trapped in the D.E.E.P), and uses his UNIT credentials to gain access to the location of the base. He has never really considered taking up smuggling. He is also known as 'Doctor John Smith'. He knew Ruth long ago as a girl with pony tails (Ruth that is) keeping her safe as part of a promise he made to Vollmer. He once told her that he could regenerate, although it's never revealed which number incarnation he is currently in.
Location: The D.E.E.P, 2039 and 2066
Links: 'Terror of the Autons' (Military intelligence is an oxy-moron.)
Bottom Line: 'If I told you I'd have to kill you'
A cheesy cliche of a line becomes the kernel of what is arguably the coldest version of the Doctor to date - and yes, that includes the Valeyard! David Collings' Doctor swears, bribes smugglers and kills people to cover up secrets - he's really quite a piece of work. A risky story to cover, which in itself must earn Big Finish some credit, but possibly the cause of a few demands for refunds from the 'real' Doctor's fans. The last scene, however, is to die for! Literally!!