The actress, whose latest film Gnomeo & Juliet opens this weekend, told DS that she will play a "very tough" character living on a farm in the sci-fi thriller.
"It's a very different kind of movie, very high concept," Blunt said. "It's dark, set in a post-apocalyptic world and it involves time travel but done in a really cool way."
She continued: "I really like what Rian's done with this script because it feels accessible, it feels like maybe we are only 50 years away from being in this realm."
Looper centres on a time-travelling assassin (Joseph Gordon-Levitt) who discovers that one of his targets is his future self (Bruce Willis).
Click 'play' below to watch Emily chat Looper:
> Click here to watch our Gnomeo & Juliet interview with Emily Blunt