Superman actor Henry Cavill went undercover at Comic-Con on Saturday (July 23) to surprise Will Smith and fellow Suicide Squad cast members Viola Davis and Scott Eastwood. The Man of Steel star also got away with walking around the convention among fans freely, thanks to a very simple disguise.

A video posted by Henry Cavill (@henrycavill) on

In a video posted to Instagram, the actor puts on a Guy Fawkes mask from the 2005 film V For Vendetta and tells fans: “Here we go I’m going to head on to the floor and see if I can get away with it, wish me luck!”

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Cavill then manages to walk past fans on the Comic-Con floor, going completely unnoticed and even checks out some Superman comics. He also poses for photos with unsuspecting fans who were wearing Superman t-shirts.

But the best part came when Cavill approached Will Smith, who was there to promote Suicide Squad, and asked the actor for a photo, before removing his mask just in time to say cheese. When Smith looks at him to shake his hand the Deadshot actor appears visibly shocked before breaking out into laughter.

Cavill captioned the funny clip: “Best Comic Con yet. I got to be here for Justice League but couldn't miss Suicide Squad. #SDCC2016 #JusticeLeague #SuicideSquad.” Cavill will next be seen as Superman in Justice League, due out next November.

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Meanwhile, Saturday’s Comic-Con also saw the debut of the first Justice League trailer. Introduced by Batman star Ben Affleck, the teaser featured Gal Gadot back as Wonder Woman, Jason Momoa as Aquaman, Ezra Miller as The Flash and Ray Fisher as Cyborg.