LONDON -- Game of Thronesfilming has started up again,Watch Human Capital Online cast sightings in Belfast have peaked, and speculation about what's in store for Season 7 is quickly gathering momentum.

We already know that British legend Jim Broadbent will have a role in the next Season, but -- as usual -- showrunners are keeping tight-lipped about new characters and plot-lines at this early stage.

Still, that doesn't mean we can't speculate.

Introducing Devin Oliver, the singer for American band "I See Stars."

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Remind you of anyone?

A few days ago, Oliver shared the following, cryptic post on Instagram.

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Hmm.

It wasn't long before the speculation started.

The Instagram post eventually made its way to the r/gameofthrones subreddit, where the speculation reached fever-pitch.

So, is Devin Oliver going to be playing Rhaegar Targaryen -- ie. Daenerys' deceased older brother -- in Season 7?

Well, despite the fact that he's a singer rather than an actor, it's always possible. As many people pointed out on Reddit, we know from the books that Rhaegar enjoyed singing, and -- given the Season 6 flashback that all but confirmed the R + L = J theory -- it wouldn't be a surprise if we were to see more of Jon Snow's real dad in the coming season.

Game of Throneshas a history of casting relatively unknown actors, too, so Oliver's lack of IMDb credits wouldn't necessarily be an obstacle.

Also, he really does look the part.

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Still, nothing is confirmed at this stage.

Oliver might be joking, or he might simply be in Season 7 in a much minor role.

Mashablehas reached out to HBO for comment and we will update this article if we receive a response.

UPDATE: Sept. 29, 2016, 5:33 p.m. BST A spokesperson from HBO told Mashablethey don't comment on casting speculation.

Bonus: Game of Thrones cast blows up social media with Season 7 news