"The Rat Tribe"

The evening sun sits low in the smoggy Beijing sky. Beneath a staid, maroon apartment block, Jiang Ying, 24, is stirring from her bed after having slept through the day. Day is night and night is day anyway, in the window-less world she inhabits three floors below ground.

Pint-sized and spiky-haired, Jiang Ying is among an estimated one million migrant workers who live beneath this city. Like millions of Chinese who come from across the country with dreams of making it big in the capital, she had travelled to Beijing from her native Inner Mongolia three years ago, and now works at a hip bar in the heart of Beijing's nightclub district. But even so, she can barely make ends meet.

Faced with sky-high property prices, living underground is often the only option for this legion of low-waged migrant workers, who make up one-third of Beijing's estimated 20 million people.

We are happy to report that Lili, the pedicurist who speaks last in the video has moved into an apartment above ground -- progress.