Imagine being filmed on a video set and realizing that Mark Hamill—yes, that Mark Hamill—was right behind you. For a number of lucky Star Wars fans, that's exactly what happened.

The fans were asked to participate in a film shoot for the Force for Change campaign (which raises funds for children's charities like Unicef Kid Power and the Starlight Children's Foundation) where they were told to recreate iconic scenes from the films. However, little did they know that Hamill was also on set to add some authenticity to the proceedings.

It is immediately apparent that Hamill takes joy in scaring the pants off his adoring fans, slowly walking behind one who was told to imagine he was standing on the sands of Tatooine and casually asking him, "How's the view?"

A highlight is at the 4:14 mark, where you can see the exact moment one of the fans realizes who's behind him after hearing Hamill's unmistakable yell.

While not everyone can have the same mind-blowing moment as these fans, Hamill also announced that Force for Change is offering one lucky fan a chance for a dinner with him through their Omaze campaign. There's no promises that he'll recite your favorite lines on command, though.

Star Wars Episode VIII: The Last Jedi is scheduled to hit theaters December 15, 2017.