Mark Hamill Reveals Secret Year-Long ‘Agony’ After Filming ‘Empire Strikes Back’

“Star Wars” icon Mark Hamill said on Twitter on Sunday that the end of filming for “The Empire Strikes Back” was especially tough on him ― because he had to keep one of the industry’s biggest secrets for more than a year. 

And he couldn’t even tell his costars. 

Hamill shared a behind-the-scenes image from the film’s climax, where he learns that Darth Vader is his father. He said a different line was spoken on the set to keep the plot twist a secret ― and that led to a year of “agony” as he had to keep it under wraps until the film’s premiere:

Hamill went into more detail on keeping the secret to the BBC in a 2017 interview that included a pitch-perfect impression of Harrison Ford learning of Luke’s parentage during the film’s premier:

Hamill has been sharing his “Star Wars” memories all month on Twitter, often playing off the “May the 4th be with you” theme of Star Ways Day on May 4. 

Over the weekend, he shared a gif of a scene that had to be redone because he botched a key line… accidentally using his character’s original name: