During ‘The Five Doctors’ a casket bearing the seal of Rassilon and containing black scrolls are discovered in the Castellan’s room. Based on this evidence he is determined to be a traitor, dying before he can clear his name.
We learn later that Borsua is the actual traitor. The Doctor confides in Flavia that he doesn’t believe that the Castellan was a traitor, based on his expression of sheer disbelief. From this we might take it that the evidence was planted by Borsua.
For the President of Gallifrey it would appear that Borsua was given significant freedom to move about as he pleased in the capital. While it is conceivable that he might be left alone in the conference room, which handily has a secret entrance to the time scoop control room, how is it that he is able to access the Castellan’s quarters or office unobserved.
A further question is when did he plant them? Once suspicion is placed upon Castellan Borsua orders his office and quarters searched. The impression given is that everyone in the conference room stays there until the search is complete and the casket is discovered.
It is possible that there is an unseen adjournment but the most likely scenario is that Borsua placed them earlier, which shows a great deal of foresight. Might he have placed similar incriminating evidence in other senior figures rooms, including Flavia’s?
The simplest answer is that the scrolls were not in Castellan’s room but that guard commander is part of the conspiracy. It does seem suspicious that he kills Castellan moments later. The weapon the Castellan supposedly used could easily have been planted.
If correct was the commander of the guards ever questioned about his involvement once Borsua’s true nature was revealed? This could be a good avenue of investigation for your own PCs, especially as we don’t know how far the corruption went.
What was the commander of the guards offered in return for his duplicity? Where did he obtain the black scrolls? What happened to him after this story? Was he just a follower or could he have engineered his own traitorous plan in the future?
The black scrolls present their own mysteries. They are said to contain forbidden knowledge and possession of them is enough to prove Castellan’s guilt. Yet the Doctor seems intent on reading one, so their contents don’t disturb him as much as the others.
Borsua specifically says that is forbidden knowledge from the Dark Tower. Does this mean that this is where Borsua obtained them? If so how did he get there since his chief motivation for involving the Doctor’s past selves was to remove the obstacles in and around the Dark Tower?
It is more likely then that he discovered the black scrolls elsewhere. If this is the case why do the black scrolls originate at the Dark Tower? This lends credence to the rumours that Rassilon was locked in the Dark Tower, suggesting that he ruled there. Alternatively it could be that he stayed in the Dark Tower in his final days, knowing it would be his tomb.
If Borsua didn’t get them from the Dark Tower where did he find them? Where they concealed somewhere within the Capital or were they in the hands of someone else who had discovered them? Could they have been recovered from somewhere else in the universe?
We don’t know what knowledge was contained within the scrolls themselves. Borsua read them but that they didn’t contain the secret of immortality itself. It is possible that it gave enough hints for him to believe that the secrets he sought were in the tombs themselves.
There are endless possibilities for what they did contain. As a pioneer of time travel it could be that Rassilon learn some secrets about temporal physics that others thought it was best not to know.
They might contain classified secrets of Gallifrey’s past, that would be embarrassing or scandalous if they were made public. ‘Trial of A Time Lord’ gives an indication of how far the high council will go to cover up the truth.
The Virgin New Adventures suggests that ancient Gallifrey accidentally allowed demonic creatures such as vampires into our universe and that Rassilon committed genocide against any race that threatened his power. An idea further developed in the Big Finish audios. One could see why this knowledge would be forbidden.
The scrolls could have knowledge about the future of Gallifrey. This knowledge could be forbidden for the same reason that the Doctor doesn’t want Amy to read River’s book in ‘The Angels Take Manhattan’. To know what is going to happens makes it a fixed point.
Shortly after the casket is opened the scrolls burst into flames and Borsua says that Castellan wasn’t taking any chances, suggesting that he booby-trapped the scrolls. Either the scrolls were treated to burn when exposed to air for a certain period or there was a concealed ignition device.
Their rapid destruction, that prevents the Doctor from examining them, throws doubt on whether these were real black scrolls at all. From Borsua’s later statements we know that he has read them but is it likely he’d burn such rare knowledge as a simple ruse?
In all likelihood the real black scrolls were concealed elsewhere. They could still be within the Capital just waiting for another villain to discover them and abuse their knowledge. The PC’s could even be tasked with finding them before someone else does.
The casket contains several black scrolls, so there is no reason to believe that they would all be kept together. By the time Borsua found them several scrolls could already have been removed and found their way into the hands of others.
We don’t know exactly how other Time Lords would react to someone posing the black scrolls. Castellan is only arrested because the casket suggests a link between himself and the Death Zone. He is being taken away so that they can use the mind probe to work out what his plan is.
Could someone be arrested for just having a black scroll? Borsua is the only one to state that is forbidden knowledge so it might not be illegal. For all of his rebellious ways it is doubtful that the 5th Doctor would be willing to break the law just to read the black scrolls.
This could led to an intriguing situation for PCs. What if they know someone has a black scroll? Does it automatically mean that they are evil or that knowledge will be misused? What if the position is reversed and they are the ones who have the forbidden knowledge? How would they react when others try to intervene?