EXCLUSIVE: How Bradley Cooper Landed a Surprise Role in Mysterious, New 'Cloverfield' Film

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Shrouded in mystery, 10
Cloverfield Lane
has become one of the most buzzed about films of 2016.

Since its trailer first debuted online, fans were surprised
and excited to learn there was another Cloverfield
film -- this one being a “blood relative” to the hit 2008 sci-fi film about an
alien monster attacking New York City.

The new movie, about a woman who wakes up in an underground bunker
with two strangers to learn there’s been a worldwide chemical attack, was so
mysterious its cast -- John Goodman, Mary Elizabeth Winstead, and John
Gallagher, Jr. -- didn't even realize that both films were connected until the
very last minute.

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“We all just follow [producer J.J. Abrams’] lead and we know that he's
got a master plan in mind when it comes to how to unveil these movies,”
Winstead tells ET. The actress herself didn’t even know about the film’s
connection until hours before the trailer was released online. “And I think he
likes to keep the experience pure for the audience, so that they come in and go
on a real rollercoaster thrill ride.”

Paramount Pictures

Part of that thrill is picking up on all the Easter eggs
that Abrams has become notorious for planting in his projects, with one of them
being a surprise cameo by Bradley Cooper. In a blink-and-you miss moment, the
actor can be heard on the phone with Winstead in the opening scene of the film.

Abrams fans will of course remember that the Oscar-nominated
actor once starred in the filmmaker’s ABC spy drama, Alias, alongside Jennifer Garner.

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“We just remained friends,” Abrams tells ET about working
with Cooper. “When we were working on the movie, I wanted you know to make sure
we had a voice that we loved. We were just talking about who would be that
great voice and so I asked, ‘What if it was Bradley?’”

“I texted Bradley and I asked him if he was interested in
doing this,” Abrams explains, “and he as the sweetheart he is texted back and
said, ‘You know whatever you want.’ He's just the greatest, so it was a very easy
thing to do.”

The cameo itself was even a mystery to Winstead, who
revealed that she filmed the scene over a year ago. “Now we get to say, ‘Bradley
Cooper is starring in our movie,’” she says. “It's pretty cool.”

10 Cloverfield Lane
hits theaters on Friday, March 11.