Aaron Paul and Bryan Cranston in Breaking Bad (Credit: AMC)

Something's afoot in Albuquerque.

Both Bryan Cranston and Aaron Paul have both posted cryptic messages on their social media accounts – of two donkeys (or are they mules?) with the caption 'Soon'.

And with that, a flurry of speculation has engulfed the internet as to what - if anything - this could mean for Cranston's Walter White and Paul's Jesse Pinkman.

The pair were last seen together during the climactic scenes of Breaking Bad, with only one of them coming out alive.

So that limits some of the potential possibilities, if a reunion is on the cards – which the posts would suggest is what's happening.

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Breaking Bad creator Vince Gilligan is working on a feature-length sequel to the series, called Greenbrier, which will reportedly centre around the kidnapping of Jesse.

But seeing as Cranston's Walter White died at the end of the series, this would need some time-line jiggling, unless he appears to Jesse as some kind of 'Force Ghost' from Star Wars.

Aaron Paul and Bryan Cranston pose with their Tyvek suits at Smithsonian's National Museum of American History on November 10, 2015. (Photo by Kris Connor/Getty Images)

Speaking about it, Cranston told The Dan Patrick Show: “It’s a great story and there are a lot of people who felt that they wanted to see some kind of completion to some of these storylines that were left open [in the series finale].

“This idea, from what I’m told, gets into those — at least a couple of the character show were not completed, as far as their journey.

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“I don’t know if there’s an appearance — flashbacks, flash forwards — but I’m excited about it because it’s Breaking Bad and it was the greatest professional period of my life and I can’t wait to see all those people again, even if I just come by to visit.”

So could it involve some kind of Walter and Jesse flashback scenes?

Story continues

Aaron Paul and Bryan Cranston, winners of Outstanding Drama Series for 'Breaking Bad', pose during the 66th Annual Primetime Emmy Awards, 2014. (Photo by Christopher Polk/NBC/NBC via Getty Images)

There's another possibility, however, that the pair could appear in the Breaking Bad spin-off series Better Call Saul, which focusses on the early career of Bob Odernkirk's wiley lawyer Saul Goodman, before he meets White and Pinkman and has his life turned upside down.

Mind you, there's also the possibility that they're in a project together that has nothing at all to do with Breaking Bad.

Whatever the case, it feels like we'll be finding out pretty soon.