Its blue collar protagonist, Curtis LaForche, played by the lantern-jawed Michael Shannon ? whose sepulchral bass tones make his every utterance sound like someone slowly dragging a coffin over a cello ? begins to suffer terrifying dreams and visions.

He responds by building a storm shelter in his back yard. It transpires that his mother was diagnosed with schizophrenia at a similar stage in her own life.

Are these simply hallucinations ? Or are they portents of darker things to come ?

Nichols, the film's writer and director, has gone on record as stating that at least part of the film owes something to the financial crisis:

"I think I was a bit ahead of the curve, since I wrote it in 2008, which was also an anxious time, for sure, but, yeah, now it feels even more so. This film deals with two kinds of anxiety. There's this free-floating anxiety that we generally experience: you wake in bed and maybe worry about what's happening to the planet, to the state of the economy, to things you have no control over. In 2008, I was particularly struck with this during the beginning of the financial meltdown. Then there's a personal anxiety. You need to keep your life on track?your health, your finances, your family.."