A new trailer for director Rian Johnson's sci-fi film Looper has landed online.  For those unfamiliar with the film, it takes place in a world where time travel exists, but is only used on the black market. When the mob wants to kill someone, they send the target 30 years into the past where a contract killer (Joseph Gordon-Levitt) does the dirty work. Things are going smoothly until Gordon-Levitt’s future self (Bruce Willis) is sent into the past to be killed. The US trailer takes a different tack than the international one when it comes to presenting the film's premise, plus it features a significant amount of new footage.  Hit the jump to watch the trailer.  The film also stars Emily Blunt, Jeff Daniels and Paul Dano.  Looper opens on September 28th.Click over to Yahoo! to watch in HD:Color me impressed with both versions of the trailer for Looper so far.  The international version mentions the villainous Rainmaker, who seems to be an important shot-caller and plot point in the film.  The US trailer doesn't mention anything about him, but it does play up on the relationship between Gordon-Levitt and Willis, a nice touch.Official synopsis:

In the futuristic action thriller Looper, time travel will be invented – but it will be illegal and only available on the black market. When the mob wants to get rid of someone, they will send their target 30 years into the past, where a “looper” – a hired gun, like Joe (Joseph Gordon-Levitt) – is waiting to mop up. Joe is getting rich and life is good… until the day the mob decides to “close the loop,” sending back Joe’s future self (Bruce Willis) for assassination. The film is written and directed by Rian Johnson and also stars Emily Blunt, Paul Dano, and Jeff Daniels. Ram Bergman and James D. Stern produce.