Does a new Doctor Who clue hint at the return of more Time Lords?

In the shot in question, we see Bradley Walsh’s Graham fiddling with a glowing cube inside the Tardis – innocuous enough in a show filled with random sci-fi gadgets. But fans have already begun to wonder whether this cube could be more significant than it appears, calling back to a bit of Time Lord tech that’s appeared in both the classic and modern series.

Specifically we’re talking about Hypercubes, also called tesseracts (a name that the Avengers franchise has slightly spoiled), which are a kind of time and space-travelling container Time Lords used to send messages to one another. First appearing in a story starring Patrick Troughton (specifically The War Games), the hypercubes were established as a primary mode of communication for the species, recording and storing a Time Lord’s words or thoughts and sending them throughout the universe (and different time periods) without possibility of interception.

Later, after being mentioned regularly in spin-off media the hypercubes made their return to Doctor Who in Neil Gaiman’s 2011 episode The Doctor’s Wife, when the Doctor (Matt Smith) received one emblazoned with the symbol of his old friend The Corsair, and containing a distress signal within.

Later, it was revealed that the cube had arrived too late and the Corsair had already been killed by living planet House (Michael Sheen), where the Doctor discovered a cupboard full of Time Lord hypercubes endlessly playing frantic cries for help.

So could this new cube be a message from a Time Lord? Well, it’s possible. Obviously in the form of Sacha Dhawan’s Master we’ve just had one Time Lord return to the series, and if he’s escaped from his predicament it could be a message from him to tease a future clash.

Alternatively, it could be another hypercube arriving too late, sent from some resident of Gallifrey to try and call for the Doctor’s help during the Master’s attack. And given that it’s Graham using it, could this be when the TARDIS team discovers that the Doctor still isn’t telling them the whole truth about her background?

Or maybe there are some other Time Lords out there who survived the Master’s attack and who are looking for help from the Doctor. In which case, it could be time to learn some new professional sounding title-names…

On the other hand, it could be that we’re overthinking this whole thing and this nifty-looking glowing cube is just that – a cube. After all, it seems unlikely the BBC would give away an important plot point (or even just a fun Easter Egg) in a publicity image, and there’s no reason that every sci-fi looking cube has to be one of these devices. In 2013 there was an episode full of sci-fi cubes (Chris Chibnall’s The Power of Three) all of which had nothing to do with this bit of lore.

The cube also looks pretty different to the versions we’ve seen before – though, to be fair, the depiction of the hypercubes did also change between 1969 and 2011, so there’s no reason to suppose there couldn’t be another design tweak again.

Overall, we just don’t think it’s too likely that Doctor Who would so quickly jump back to the well of Time Lord society quite so soon, and it seems more likely this cube is just what it looks like – a weird sci-fi gadget with some relevance to this week’s story only.

Though if you disagree, please do let us know why – answers via glowing psychic containers only, please.

Doctor Who continues on BBC One on Sundays