Part of the fun of each new season of Game of Thrones is that, as we're beyond much of what has been told in the books, any new information is something we can speculate about. So get your fan theorising ready as another very surprising character seems to be returning for season seven.
The eagle-eyed folks at Winter is Coming have noticed that David Bradley — best known to Thrones fans as the evil head of House Frey, Walder — has updated his United Artists agency resumé to include a credit as Walder Frey for Thrones' upcoming seventh season. That would be interesting in and of itself, considering that the last time we saw Walder Frey, he was the inaugural stop on Arya Stark's Killtacular Killing Spree Westeros Tour 2k16:
So how is he back in action now? Here are a few scenarios we thought up of that could necessitate Bradley's return as anything more than a corpse:
A Straight-Up Flashback
This would probably be a solid choice, either for some other Frey-based story that Walder was part of before his demise, or Arya telling her fellow Starks — whom she's heavily rumoured to be reuniting with this season — what she's been up to for the past five years while they have been gallivanting off around Westeros (and dying, mostly, as is the Stark tradition). Game of Thrones rarely does straight-up flashbacks, but Cersei did have one back in season five. Still, if it's a flashback, it's much more likely to be done as...
A Bran Vision
Slightly different from a flashback, but Walder's return could be part of a vision that lets Bran know his sister is not just alive, but has taken a fancy to slashing people's throats since the last time he saw her. Or he could be looking at some of Walder Frey's nonsense from the past. Or he could be a witness to the Red Wedding, which I don't believe he knows of for sure yet — and Bran actually being present at the Red Wedding, vision-style, could necessitate some new footage of Frey.
Arya Impersonating Him With Her Face-Changing Abilities
Now that she's offed Walder Frey from her list, Arya has some catching up to do for the Killtacular Killing Spree Westeros Tour 2k16. Maybe she'll have to borrow Walder's face for a bit, to hide his death and facilitate her revenge plans? Or, she could even use his face to show off her assassin abilities to her siblings, if they do indeed reunite as rumoured this upcoming season. Also, just think about how hilarious/horrifying the CG magic of making tiny Maisie Williams turn into ancient David Bradley and vice versa would be.
He Gets Resurrected by a Red Priest
Possible, but this seems a stretch. It's tough to imagine why a Red Priest or Priestess would bother bringing him back from the dead, and no one liked Walder Frey anyway. Unless...
Walder Frey Is the Show's Answer to Lady Stoneheart
This is very unlikely, but after the years of teasing Stoneheart's existence and her absence from the show's narrative, could you imagine the reaction to zombie Catelyn Stark's role from the novels being given over to Walder Frey? It'd be amazing, not just because of the magnitude of the twist, but also because of how fans would freak out. (We'd certainly freak out.) Of course, it would be a bit bizarre for Lord Stoneheart to end up leading the Brotherhood Without Banners, as Lady Stoneheart does in the books, as the Brotherhood are mostly fighting the Lannisters, with whom the Freys have allied. If Game of Thrones' endgame actually needs an army led by a surly zombie, Frey would make a very interesting candidate.
As always, provide your own wild speculation in the comments below!