The meme featuring James Franco backing off with a dagger comes from the 2002 superhero film 'Spider-Man.' In this scene, Franco's character, Harry Osborn, is hit with the shocking realization that his best friend, Peter Parker, is actually Spider-Man. This revelation causes him to back away in disbelief, a moment underscored by the dramatic score of 'Lux Aeterna' by Clint Mansell. This iconic scene is etched into the minds of moviegoers due to its dramatic tension and the intensity of Franco's performance, which has been humorously repurposed in the meme world to capture moments of sudden and shocking realization.