The phrase comes from Game of Thrones, where Melisandre, the red priestess of R'hllor, uses it as a warning and prayer to the Lord of Light, the fire god worshipped in Essos. In the HBO series, which ran from 2011 to 2019, she repeats the line before rituals, battles and moments of prophecy, turning it into one of her most recognisable sayings. Fans later clipped it for edits, reaction videos and soundboards, where its ominous tone fits horror, fantasy and dramatic reveals far beyond the original show, keeping it in circulation long after the finale.