With his new crime thriller 'Nightcrawler', Jake Gyllenhaal put a lot of himself into bringing a particularly unsettling character to life, namely by losing a lot of weight. But what was it about this movie that drew so much commitment from him?

Jake Gyllenhaal in 'Nightcrawler'
Jake Gyllenhaal looking gaunt in 'Nightcrawler'

Dan Gilroy's directorial debut has seen a stream of positive reviews since it premiered at the Toronto International Film Festival in September 2014, and that's probably down to Jake Gyllenhaal's overwhelmingly unnerving interpretation of insistent and rather ghoulish crime journalist Louis Bloom. 'Lou is a creation of the American dream', Gyllenhaal explains. 'We're all told about this conventional idea of what success is and he'll do anything for it. Ultimately, it's someone like him who becomes one of the most successful entrepreneurs in America.'

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The actor's attachment to the character, who presents the rather immoral situation of being an observer of grisly crimes in aid of a front page headline, was largely brought about by Gilroy's script. 'The highlight of the movie, for me, was the dialogue', he admitted. 'I just loved saying Dan's words; I followed them like an orthodoxy, literally word-to-word. If I messed anything up, I'd want to do it again because I think his words really are special. Every time we'd finish a scene and we'd move on, I'd always be sad that I would never say them again.'

Watch the trailer for 'Nightcrawler' here:

Indeed, Gilroy was visibly impressed by Gyllenhaal's efforts and stoic approval of the story, admitting 'it's rare to have someone come in and push themselves as hard as he did'. It was clear from early on that the star was serious about putting energy into the role, when he appeared looking particularly gaunt in the run up to filming. 'He lost about 25 pounds', Gilroy reflected. 'It all makes sense now but there was a time when it looked vaguely scary. I just felt it was a phenomenal transformation.'

'Nighcrawler' will be theatrically released by Open Road Films on October 31st 2014.