The mini-episode ‘Death Is The Only Answer’, written by the children of Oakley CE Junior School, reunites the Doctor with Albert Einstein (after they last encountered each other on-screen in ‘Time and The Rani’) and an Ood (who seem to be popular in these mini-episodes).
The episode begins with the Doctor (apparently alone) talking about how he had missed the TARDIS and couldn’t believe that River had blown it up. This establishes this story as taking place relatively soon after ‘The Pandorica Opens’.
Conceivably Amy and Rory could be elsewhere in the TARDIS after he collects them from their wedding in ‘The Big Bang’. However as the Doctor enters with the fez he picks up in the alternative timeline I think this probably occurs before the wedding, after the universe is rebooted and he is about to be summoned by Amy.
The Doctor trips, dropping the fez on the TARDIS controls and pushing a lever that causes it to vanish. It eventually transpires that the fez returns to its original owner, Albert Einstein, and creates a time window for the him to pass through into the TARDIS.
This indicates that the TARDIS can teleport objects and people from and into itself. Einstein is surprised that the fez is on his head, suggesting that this was the ‘hook’ that the time machine to reel him in.
If a TARDIS pilot becomes skilled with this technique the time machine need not ever land. Instead crew members can be sent where ever they need to go and then recalled via a time window.
Einstein at first believes that his transportation was the result of his own time machine. The Doctor is sceptical of this, using air quotes when referring to Einsteins ‘time machine’. Indeed this seems justified as developing the device has caused Einstein to almost die twice and fall off a cliff.
We learn that Einstein tried to steal the TARDIS in the past (and possibly succeeded). This could be where he first had the idea to create his own time machine. This original incident could be the basis of an adventure, whether it occurs directly after ‘Time And The Rani’ or at a later point.
He believes that he is close to perfecting it using a green fluid he refers to as a bionic fusion liquid. Since he was by his time machine when the time window appeared it is likely that he was just about to use it on the machine.
Shortly afterwards Einstein throws doubt on the exact nature of the liquid. He claims to have invented it and refuses to allow the Doctor to test it. How is it possible that Einstein created the fluid, named it and doesn’t know what it is?
Later Einstein asks the Doctor to take him back to 1945. From 1943 Einstein was a consultant for the navy, working for a research chemist Stephen Brunauer. Could it be that Brunauer provided the unknown chemical for Einstein?
Just as the Doctor is warning Einstein not to drink the fluid the green ooze spontaneously squirts over the scientists face. This results in a rapid transformation into an Ood, complete with translation sphere.
The physical transformation is reminiscent of the toxic slime in ‘Inferno’. It could be that Ood has a common ancestry with humans that the slime unlocks (although this doesn’t explain the sphere). It might also be that this creates a genetic flux that the Ood take advantage of, using Albert as a temporal host for one of their psychic projections (much as they appeared to the 10th Doctor in his last days).
The title of the episode comes from the Oods ominous claim that ‘death is the only answer’ The Doctor doesn’t understand this and wonders what it could be the answer to. Could it be the answer to the very first question? The question he has been running from his whole life?
It could also be that this Ood originates from ‘The Time of the Doctor’ and decided that the only way to end the stalemate was to kill the Doctor earlier in his timeline. If it isn’t an assassin it could be just trying to let the Doctor know that the same situation can be solved by his ‘death’ and subsequent regeneration.
The Doctor distracts the Ood by saying that it is looking for a power source for his time machine. This could just be a theory but if true it might mean that the Ood had taken over Einstein and had been driving him to create a time machine so it could get home.
Producing the supposed power source from his pocket and throwing it into a barrier of silver energy activated by a lever on the console. Passing through this energy field restores Einstein to normal. This indicates that the Doctor had at least some idea what had happened and that the energy some how filtered out the mutation.
Like ‘Good As Gold’ the mini-episode ends on a cliffhanger. After the Doctor has returned Einstein home (empty handed) and he puts the TARDIS back in flight the camera lingers on a dollop of green liquid on the floor which begins to move on its own.
This indicates that the fluid itself was alive, explaining how it came to spray over Einstein. This raises more questions about its origins and possible agenda. Could it still be in the TARDIS waiting to infect someone else?
There is certain sense of urgency to the Doctor’s use of the TARDIS console. This could indicate that he is rushing to somewhere unconnected to these events (like Amy’s wedding) or he has realised that there are too many unanswered questions about this incident.