The Toronto film festival opened with a science fiction film, American director Rian Johnson's time-bending mob thriller "Looper." It was written as a short film more than a decade ago when Johnson was deep in Philip Kindred Dick's novels, which inspired blockbuster movies such as "Blade Runner," "Total Recall" and "Minority Report." Johnson said he returned to the idea after the 2008 Toronto festival, or TIFF, premiered his film "The Brothers Bloom," a follow-up to his debut feature "Brick" (2005). "With 'Looper,' Rian has taken his filmmaking to a new level," TIFF's artistic director Cameron Bailey said. "This is a new kind of opening night: an exciting, thinking-person's action film from a director who really understands the genre." Starring Emily Blunt, Paul Dano, Noah Segan, Piper Perabo and Jeff Daniels, "Looper" recounts the fantastical tale of a hired gun (Joseph Gordon-Levitt) who mops up 30 years in the past from 2072 for the mob until his bosses send back his future self (Bruce Willis) for assassination. What follows is an emotional and violent rollercoaster ride as every action is examined for its consequences. "Looper at its heart is about violence," said Johnson. "There is quite a lot of violence in it, but (at its core) it's about the self-perpetuating loop that occurs when the solution to a problem is, 'Let's find the right person and kill them.'" "It's essential in our culture to have stories that address that," he told reporters. In recent years, TIFF has opened with a U2 rockumentary, a hockey musical, a Charles Darwin biopic and a World War I epic. "Looper" reunites Johnson with his friend Gordon-Levitt, who also appeared in "Brick." But in a challenge to the filmmaker, the casting has Gordon-Levitt, as the younger lead character Joe, looking nothing like his older self -- Willis. Johnson said a lot of makeup was used, but mostly it was left up to Gordon-Levitt to convince audiences that he could swagger like a young Willis. Gordon-Levitt said he studied Willis's past films, listened to audiotapes of Willis reading some of his lines in "Looper" and hung out with Willis to learn to mimic his tough guy hero mannerisms and serious tone in films such as "The Fifth Element" (1997) and the "Die Hard" series. Willis called Gordon-Levitt's onscreen transformation a "magic trick." Some settings in the film were more easily swapped during production, which would have audiences laughing. In the opening scene, Joe is listening to audiotapes to learn French, in hopes of moving there some day, but is later warned by a time-traveler from the future not to go to Paris. Asked why he thought Paris would be scary in 2072, Johnson said a sequence in the script was originally set in the French capital but was replaced with China at the last minute due to budget constraints. "It's not that we think that (a future) China will be better than Paris, it's more that we didn't have the budget to go to Paris," he said. The location choice was not a commentary on the eurozone debt crisis or China's rise. Johnson said he considered filming the scenes in New Orleans and use special effects to fake Paris but his Chinese distributor offered to co-produce the film if he came to Shanghai instead to film the scenes. So he did. The film festival, which runs from through September 16, is the biggest in North America and has traditionally been a key event for Oscar-conscious studios and distributors. Unlike the Cannes and Berlin festivals, Toronto does not have an official competition or award jury prizes, but an audience prize is handed out and the winners often go on to win big at the Academy Awards. "Looper" will be in theaters at month's end.