Synopsis: Now ten years after the events in "The 4-D War", an older Lady Rema-Du is attending a trade conference on Deserault. The goal of the conference is to establish uranium mining rights on the planet, whose inhabitants ostensibly have no way of extracting the uranium themselves. Three delegations have come to place bids: the Gallifreyans, the Black Sun, and the Sontarans.
Rema-Du's father, the now extremely elderly Griffen, has traced the beginning of hostilities between the Order of the Black Sun and Gallifrey to this moment in history. However, the Black Sun delegates all seem completely amiable. Griffen supposes that the Black Sun, despite being a time traveling culture as well, don't necessarily know that 30,000 years hence they are at war with Gallifrey. Indeed, so much does Rema-Du come to trust the Black Sun, that she falls in love with Adamath, a Black Sun ambassador. Consequently, the two delegations put together a joint bid for the uranium, which leaves the Sontarans out in the cold.
Just as the conference concludes and the Desaraulti are about to announce that the Gallifrey/Black Sun bid has won the rights, a jealous Brilox sets in motion the Sontaran "counter-offer". He mindwipes one of the Gallifreyan security guards and has her gruesomely kill a Black Sun elder on the ceremonial dais, to the shock of all those in attendance. Wardog puts down his colleague on the spot, ostensibly hoping to avert any further bloodshed.
Later, he uses the Sontaran's mindwiping device on him. The Sontaran is left alive, but with a completely blank mind.
Notes: The real question with this concluding story is whether it merely shows the beginning of the First Great Time War or if it shows the end. All we know for sure is that the proximate cause—Brilox' manipulation of a Gallifreyan agent to kill a Black Sun elder—is detailed here. But Wardog's swift actions in neutralizing both Brilox and his Gallifreyan pawn—not to mention Rema-Du's romance with a Black Sun ambassador—might well have averted the war. The temporal paradox factor on this story is almost impenetrably high.