This film is about a woman who is kidnapped by a survivalist who claims he saved her life and forces her to stay with him in his survival bunker. It was originally going to be called 'Valencia' but it was all a trick!
The twist here is that the creepy survivalist kidnapper totally did save her life because this is the SEQUEL TO CLOVERFIELD. Actually, according to Collider, J.J. Abrams has called it more of a "blood relative" than a direct sequel.
The movie is still going to be directed by Dan Trachenburg who got a lot of attention in the past for his short film based on the video game Portal.