As the far flung characters on Game of Thrones come closer together in the seventh season, there are a few people who seem to have dropped off the map at the moment, one of which being the morally shaky (at best) Red Woman. Where is Melisandre on Game of Thrones? From the trailer at least, it looks like she's still going to have a part to play in the coming war.
Let's start from where we left off. After Jon became King in the North, Ser Davos informed him that Lady Melisandre, the woman who brought him back from the dead, had ordered Shireen, the young daughter of Stannis Baratheon, to be burned at the stake as a sacrifice to the Lord of Light for reasons. Jon, ever the noble Stark, banishes Melisandre from the North forever. Because Melisandre is committed now to the idea that Jon Snow is the prophesied Azor Ahai, as she once believed Stannis was, this is unlikely to please her. She makes a brief appearance in the trailer for Season 7, and it looks as though she's standing on Dragonstone, where Daenerys Targaryen and her people have established themselves. Is she switching sides? Is she going to try some diplomacy? What is Melisandre doing there?
Before Melisandre realized that Stannis Baratheon was not the Prince that was Promised, she lived at Dragonstone with him. Oh and they conceived a murderous smoke baby on Daenerys's cool map table. Perhaps she returned out of nostalgia, or simply a lack of anywhere else to go. Maybe she has a plan to convert Daenerys to her religion and attempt to broker some sort of alliance between her and Jon Snow.
It is widely speculated that Jon Snow and his army will be making their way to Dragonstone in the near future as well. Jon is on a mission to mine and collect as much dragonglass for weapons against the White Walkers as possible. And Samwise Gamgee, sorry Samwell Tarly has just learned that Dragonstone is sitting on a literal mountain of dragonglass. This information is probably going to bring Jon to Dragonstone posthaste, where he will meet Daenerys, and apparently Melisandre.
I don't know if Jon is capable of forgiving someone for murdering a child in the name of a vague fire god. If he is, then this meet up is going to be far more interesting than we realized.