Given how great Swinton’s performance is, it’s a sad moment in the movie — but as co-writer Jon Spaihts recently explained to me, it was a necessary choice in the script.
While Tilda Swinton proves to be absolutely amazing as The Ancient One in Doctor Strange, the sad truth is that her stay in the Marvel Cinematic Universe is… short-lived.
Because the presence of a Sorcerer Supreme naturally has the effect of undermining the abilities of the titular hero.
Thanks to a battle with a super-powered Kaecilius in the mirror dimension, The Ancient One winds up taking a great fall in the middle of New York, and sadly the team of emergency room doctors led by Christine Palmer are unable to save her.