Game of Thrones Season 6 returned with one of the series' favorite nudists, Melisandre, stripping down in a dingy mirror at Castle Black and then — magically! — turning into an old woman before crawling into bed. But who is the old woman Melisandre became?
The necklace she removes right before transforming is our clue. Melisandre wears a ruby around her neck, which glows red every time she performs a magical feat, via powers bestowed upon her as a priestess of the Lord of Light. Since she sheds the necklace right before transforming, we can safely guess that it harnesses some or all of her power, which also keeps her appearing young and beautiful. The better to seduce possessors of King's Blood with, my dears! Without the necklace, she becomes the withered, feeble, positively ancient woman, upon whom she sadly gazes in the mirror.
Showrunner David Benioff has confirmed that Melisandre is actually "several centuries old," with Carice van Houten (the actress who plays Melisandre) saying on two different occasions that her character is "way over 100 years old" and "400 years old." She's already survived a poisoning, so we know she can cheat death seemingly better than anyone else is Westeros. (OK, Tyrion is a close second.)
Vanity Fair also points out multiple passages in the books that imply Melisandre is or could be immortal. But their most compelling argument surrounding Melisandre's transformation is perfectly pegged to the long, full body shot we see of the old, nude woman:
Viewers who turn to the show just for titillation are forced to confront the fact that the woman they’ve been objectifying (and who has been using her youthful body to gain power) for five seasons is in fact elderly.
This is a super interesting idea, if the series chooses to explore it further, that could significantly complicate and deepen Melisandre's character. We know her as a somewhat shallow, seductive, cunning woman with a little bit of a mean girl vibe that presumably comes from getting everything she's ever wanted handed to her, thanks to her rockin' body and great hair. But if she really is hundreds of years old, then she's probably seen some sh*t. She's likely lived at least parts of her life in her old woman form, with all the invisibility that comes accompanies women of age. This could be a huge source of depth audiences are gaining for her character and motivations.