The cue is Hello Zepp, composed by Charlie Clouser for Saw, the 2004 horror film directed by James Wan. Named in reference to the character Zepp Hindle, the track plays as the final twist recontextualises everything before it. Clouser reworked the theme in variations across the sequels, making it the musical signature of the franchise's ending reveals. Online, the clip spread through edits, memes and soundboards as shorthand for a dark twist, with listeners recognising the rising piano long before the payoff arrives.