The film is about what happens when the apocalypse comes while a bunch of stars are partying at Franco's home, E! said.
"Just leaving set!" Rihanna tweeted. "This has to be one of my favorite moments in life."
"Comedy is brutal," Watson said on Twitter. "New Orleans is the best!! : ) See you all soon. Em. x."
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NBC reportedly holds celebs hostage to Jimmy Fallon's show