Looper trailer shows Joseph Gordon-Levitt as a young Bruce Willis

There's something strange about Joseph Gordon-Levitt's face…

The 'Inception' and 'Dark Knight Rises' actor stars in 'Looper', about a hit man who kills targets sent back in time by an evil crime organisation. He doesn't question his work, until the man who appears in front of him is... him - from 30 years later.

Check out the new UK trailer below.

It's an intriguing premise that nonetheless created a major headache for writer/director Rian Johnson. Bruce Willis plays Gordon-Levitt as an older man, and the pair look nothing alike.

Speaking to our US Movies team, Johnson said: "Bruce was perfect for the part in so many ways, but that was one big challenge, the physical differences between them."

He said they didn't want to totally change Gordon-Levitt's appearance and instead wanted to "take a couple of key facial features and tweak them, just to give the audience something to grab on to." Nonetheless, the make-up took three hours a day.

You'll notice Gordon-Levitt also sounds rather a lot like Willis. Apparently the actor spent hours listening to dialogue from Willis' films such as 'Sin City' to nail the gravelly tone.

You can see if Gordon-Levitt gets it right when 'Looper' is released in the UK on 28 September 2012.