Game Of Thrones Season 6: 8 Things You Might've Missed In 'Oathbreaker'

Although Melisandre saw Jon Snow in her flames last year, she was still backing Stannis. Since Season 2 she had not only supported him, but truly believed that he was the reincarnation of Azor Ahai, the Prince that was Promised (although these could be two separate people, she did think they were one and the same).

Now, though, after his death and the resurrection of Snow, she's backing a new horse in this race. She only appears briefly in the episode, but her words are pretty telling: "Stannis was not 'The Prince Who Was Promised,' but someone has to be."

Clearly she feels that someone is Jon. He has long been one of the front-running candidates, if the character will ever exist at all anyway, and his rebirth does only bring him closer to that, hence Melisandre's interest. This gains further significance given that it comes in the same episode as the Tower of Joy, which may hold the truth about Jon's lineage, and if he is indeed the blood of the dragon.