When the protagonist’s plot fails at the last minute, but just when it seems that all hope is lost, it turns out that the failure of this plot was all part of the PLOTTIER PLOT OF SECONDARY CHARACTER, who knew all along that they couldn’t succeed unless Protagonist’s plan failed, or that this failure would open up an opportunity for an even greater success that they’d been cleverly working towards the entire time.
Often seen in heists and thrillers, but a surprising number of fantasy novels too, and even romances. I’m such a sucker for the secret mastermind reveal.
What about you, what’s your favorite trope?
Most recently, there was a moment in Ink Blood Sister Scribe like this. Other fantasy examples I can think of offhand include Six of Crows and The Library at Mount Char.