the.com/retcon
rewriting yesterday's story so today's plot twist looks like it was planned all along.
means a retcon is when a new piece of fiction quietly changes established facts from earlier canon to fit a new narrative need.
from short for retroactive continuity, coined in comic-book fandom circles in the 1980s to name what writers had been doing for decades without a word for it.
early examplejean grey's death undone via clone in x-men
soap opera rootssoaps used the trick long before comics named it
star trek termfans call some retcons plot holes patched
corporate usefranchises retcon to erase inconvenient sequels