April 1986. After the reactor explosion at Chernobyl, a radioactive cloud drifts over Poland, and the world learns of the disaster from radiation readings rather than from Moscow. Over four days, scientists at the Central Laboratory for Radiological Protection raise the alarm while the communist authorities weigh public safety against loyalty to the Soviet Union: children are given Lugol's iodine, but the May Day parade and the Polish cyclists' start in the Peace Race in Kyiv go ahead. A Polish Television Theatre play based on real events.