Roots: Puccini's Madame Butterfly, the Doctor quotes from Emily Dickinson.
Double Entendres: "I'm quite aware you can do this without intervention. I like the stimulation."
"As soon as I'm under I want you to blow the airlock door" (followed by the sounds of sustained heavy breathing)
Dialogue Triumphs: The Doctor to the strains of Puccini: "No! I will not die to elevator music!"
Continuity: The Dar Traders, otherwise known as 'Death Collectors', are an ancient people whose cultural obsession is death itself. Their genome can assimilate parts of other species' DNA, in particular immunity to disease, with the result being that the Traders are effectively immune to any biologically based disease and by extension technically immortal. It being beyond their natural state then, the Traders share an aesthetic fascination with death. Known to be salvagers of the dead, they scavenge the aftermath of battles and revere their collections, often displaying them as trophies on the walls of their ships and dressing in the remains of the deceased. Resembling husks contained within metal frames for support and ease of movement they are themselves dead, at least physically, while maintaining a 'feverish' mental presence. The Traders claim to have 'mastered' the ability to reanimate the dead (the Doctor suggests this isn't a natural ability), holding back the last seconds of life by 'trading' or can reanimate anything that's dead by 'trading' with it - introducing their own flesh into the body of the dead. As such the Traders' activities and interests are restricted to the dead - they have no claim to the living, those who still exist within corporeal boundaries. If a 'Tradee' is still alive at the time of the DNA trade, they too gain the immunities the Dar Trader has at the time, including potential immortality. A Trader ship can contain hundreds of individuals, usually 'sleeping', as only two are required to be revived for operating the vessel at any time. The Traders say they've developed strong resistance to Decay and through their sensitivity to it can detect and follow its 'trail'.
Antikon's Decay is an alien intelligence whose natural state is a deadly and unstable biological virus contracted by unknown means (the Doctor thinks touch may be one, although the radio broadcasts appear to be another). Like the Dar Traders the Decay also exist on the threshold of life and death. The Decay 'communicate' through the biological process of death itself, attacking a living host and effectively killing it while allowing the victim to outlive their physical body for a time - advanced stages of the virus render the host body to dust. The Doctor has seen before what Decay can do to a person and it isn't pretty. After an outbreak that decimated an entire system the planet Antikon was quarantined by law with an exclusion zone of 5,000 miles [and] dampening satellites containing the Decay on its surface.
The Doctor's respiratory bypass system allows him to survive for up to three minutes without a suit in the cold vacuum of space (see Links). He has heard of Professor Mors Alexandryn for his authority on Decay and his dubious theories on death (his paper on flesh resurrection was "quite remarkable, if utterly flawed"). Mors is listed as missing, presumed dead.
Location: A sky station in the stratosphere of the planet Antikon
Links: Doctor Who. The Doctor makes use of his respiratory bypass system. The Doctor's earlier (and first) meeting with the Dar Traders is detailed in the Fifth Doctor Companion Chronicle The Darkening Eye. The Doctor's ability to withstand the cold of space is also demonstrated in Unregenerate!
The Bottom Line: "Death is merely a science, Doctor. Measure it correctly and a cure can be found"
Another high concept piece from Sheargold. The ideas are alternately baffling and clever, but the mood is as you'd expect rather downbeat and nihilistic, this being intended as something of an overture to the seventh Doctor's last days.