When collector John Maloof bought a box of old photographs from a Chicago auction house, he fell in love with the candid street shots and compassionate portraits. He set about trying to discover who the artist was. It turns out that the photographer, Vivian Maier, had worked as a nanny for many years, practicing her art in secret and never publishing her work. Several former charges reminisce about the strange and elusive woman they had once known. Maloof unravels some of Maier’s history while giving her work the exposure she may, or may not, have desired.

This investigative inquiry uncovers deepening layers of mystery as Maier the woman comes into blurry focus at the same time her striking work emerges into the art community. Preferring pictures of unsuspecting passersby or working-class street scenes, Maier’s art can also be read as a mirror image of her own isolation, and (perhaps) mental instability. As Maier’s personal background and existence are explored (she died in 2009), fundamental questions are raised about an artist’s privacy, and whether a great one has an implicit duty to share his or her work. Like the individual it portrays, this doc is a true find.