Unknown Quantity. 2005. Germany. Directed by Andrei Ujică. With Svetlana Alexiyevich, Paul Virilio. DCP. In French; English subtitles. 67 min. In this theatrical version of a gallery installation, the French philosopher and cultural theorist Paul Virilio and the Belarussian Nobel laureate Svetlana Alexievich, author of Voices from Chernobyl: Chronicle of the Future, grapple with the man-made tragedy of nuclear catastrophe and its implications for irrationality and fear in decision making and technological innovation. With shades of Andrei Tarkovsky’s Stalker—the heroic men and women who volunteered to contain the Chernobyl meltdown referred to themselves, in fact, as “stalkers”—Virilio and Alexievich venture into a black-box zone of epistemological and ontological uncertainty as they contend with human yearning and hubristic overreach, the myth of progress, and the awful, annihilating vastness of destruction in Chernobyl, seemingly as unfathomable as that of the atomic bombs in Hiroshima and Nagasaki, or perhaps even September 11.