Najprawdopodobniej postacią z końcówki odcinka jest Nocny Król sprzed tysiącleci. Trzynasty dowódca Nocnej Straży, o którym opowiadał Bran w Nocnym Forcie.
(Nawałnicy Mieczy - II część, 160 strona - stare wydanie)

Wedle tego pochodził z Winterfell. Zakochał sie w kobiecie, pasującej opisem do Innych i być może pod jej wpływem przejął kontrole nad znaczną częścią muru. Wyparły go połączone siły Króla Północy i Króla zza Muru.

Ile w tym wątku jest radosnej twórczości scenarzystów, a ile przebłysku przyszłej książkowej fabuły, tego się póki co nie dowiemy


Za wikipedią:
The Night's King is a legendary Lord Commander of the Night's Watch, who lived during the Age of Heroes.
History

According to legend, the Night's King lived during the Age of Heroes, not long after the Wall was complete. He was a fearless warrior, who was named the thirteenth Lord Commander of the Night's Watch. Later he fell in love with a woman with skin as white as the moon and eyes like blue stars, he chased her and loved her though her skin was cold as ice, and when he gave his seed to her he gave his soul as well.[1] (Her description matches that of the Others.)

He brought her back to the Nightfort and after the unholy union, he declared himself king and her his queen, and ruled the Nightfort as his own castle for thirteen years. During the dark years of his reign, horrific atrocities were committed, of which tales are still told in the North. It was not until his own brother, the King in the North, and Joramun, the King-Beyond-the-Wall, joined forces that the Night's King was brought down and the Night's Watch freed. After his fall, when it was discovered that he had been sacrificing to the Others (possibly in similar way to Craster), all records of him were destroyed and his very name was forbidden.[1] It is likely this led the lords of the North to forbid the Night's Watch to construct walls at their keeps, ensuring the keeps would always be accessible from the south.
Recent History

While on his way north, Bran Stark recalls stories told to the Stark children of the Night's King and the Nightfort by Old Nan, servant in Winterfell. She said some people believe the Night's King was a Bolton, a Magnar out of Skagos, an Umber, a Flint, a Norrey, or a Woodfoot, who ruled Bear Island before the ironmen came. However, she identifies the Night's King as a Stark of Winterfell and brother to the King of the North and hints his name too was Bran.

Boję się o Hodora.

Niepotrzebnie się bałem