This May Come in Handy
I just came across two tropes called (quite precisely) “It may help you on your quest” and “Someday this may come in handy,” which deal with seemingly useless items or pieces of information (respectively) that later become vital to the plot, like the time-turner in Harry Potter PoA, the Peter Panda Dance in The Pacifier, and virtually everything that Sherlock Holmes keeps in his mind palace. So with that in mind,
PLOT TWIST:
A man dies and approaches the gates of Heaven. As he draws nearer, he notices a sentinel blocking his way. They come face to face.
SENTINEL: “What’s the password?”
MAN: *sighs to let out some nerves and looks over his shoulder, making sure that no one can overhear. Looks back at sentinel confidently* “The mitochondria is the powerhouse of the cell.”
