Chekhov's gun
From Jenny Everywhere Wiki
he Collective of the Retconning Crocodiles owned a literal “Chekhov's gun” which they took with them during the race for the Frost King's treasure in the mountains of Manik. They eventually cocked and fired the gun during the stand-off between all the treasure-seekers, nicking a Wellsian's tentacle. (PROSE: The Frost King's Treasure)
Behind the scenes
“Chekhov's gun” is a literary term, named for playwright Anthon Chekhov, referring to the idea that an element introduced early on can and should be relied upon to become significant in the plot later on, no matter how trivial it initially seems; the example given was a prop gun hanging on the wall in the set of a play, which audiences can trust will be fired in some momentous fashion before the final act.
