After Jon Snow came to a very stabby end in the Season 5 finale of Game of Thrones, theories have abounded as to whether the character was dead for good or not. Throughout the years, the HBO series hasn't balked at killing its darlings, but many fans feel some characters were too important to be killed off: namely, Daenerys Targaryen, Tyrion Lannister, and Jon Snow. Jon has been built up with a fairly traditional hero's arc, from his rough beginning to his mysterious parentage to his magical sword and canine companion. It seemed like a lot of buildup to end with him abruptly bleeding out in the snow, and actor Kit Harington has been spotted on set for the upcoming season. It seems certain he'll be returning in some capacity, but how will Jon Snow return in Season 6 of Game of Thrones?
The show has been playing coy in the lead-up to the new season, but now that Jon Snow has shown his face in some of the promotional material, it's a definite that he'll be back in some capacity – even if it's just to stay corpse-still while other characters chat around him. There are no book spoilers to go on now that the show has outpaced the novels, so it's not as easy to predict the outcome as it's been with other Game of Thrones deaths. The question is whether Jon will stay dead or be resurrected. There are hints about the latter; the Season 6 premiere episode is called "The Red Woman," which has important connections to a certain mystical priestess.
Jon's narrative importance has been clear from the beginning and there are a couple of big fan theories that Jon Snow may very well be the answer to. One of the biggest is R+L=J, which hypothesizes that Jon is actually the child of Ned Stark's sister Lyanna and former crown prince Rhaegar Targaryen. This would give Jon a claim on the throne of Westeros. The books have also featured a prophecy of a hero and warrior called Azor Ahai who will defeat the Others (a.k.a. White Walkers) with a magical flaming sword. Jon already has his very own special sword made out of Valyrian steel that he has already used (successfully) against White Walkers. There is a lot of potential story left for Jon — it all just hinges on him rising from the dead.
This is where the Red Woman comes into play. That sobriquet is usually given to the Red priestess Melisandre, a woman of incredible power who has spent her time on the show (up until now) trying to get Stannis Baratheon onto the throne. That ended up being a no-go (RIP Stannis) so she'll need to turn her attentions elsewhere, and she's had a pretty definite connection with Jon Snow even if it's not totally clear what that connection means yet.
She arrives at the Wall not long before Jon is stabbed to death by his fellow Night's Watchmen, which would put her in the right place at the right time to do something about it. It also bears noting that in the books, Red priests have the ability to bring people back to life. It's not something we've seen Melisandre do yet, but after she gave birth to a murderous smoke baby, I would assume she can do pretty much anything.
For right now, Game of Thrones is holding on tight to its big reveal — whatever that reveal might be. Kit Harington could've just gotten paid to take a nap in the snow for an episode or two, but it seems increasingly likely that there are much bigger things in store for Jon.