"You'd be surprised what the human mind and human body can adjust to," says Greg as we follow him down a subway tunnel at Penn Station, New York City, just before a small, subterranean shanty town is shown. Greg then goes on to reveal he's been living in these dank and rat-infested conditions for roughly six years - although some of the other inhabitants have been there for decades.
That people can live relatively comfortably in these conditions is at first unthinkable, but director Marc Singer spent the best part of two years living this life while filming it in grainy black-and-white for his debut documentary feature, Dark Days. And while he certainly reveals tales of regret, self-pity and naked grief (witness crack-addict Dee's tearful tale of how her children died in a fire), he also shows that these people have a strong sense of community, humour and self-respect.
Dark Days has already won a clutch of awards at last year's Sundance, and they're well-deserved - this is a wonderfully shot and snappily edited film which succeeds in making you like and care about the kind of people you wouldn't even normally make eye-contact with.
A triumph of documentary film-making.