This film by David Bickerstaff and Phil Grabsky uses Mario Petrucci’s award-winning poem "Heavy Water" to tell the story of the Chernobyl nuclear explosion and its catastrophic aftermath. On April 26th, 1986, reactor four at Chernobyl Nuclear Power Plant explodes, sending an enormous radioactive cloud over northern Ukraine and neighboring Belarus. The danger is not immediately communicated and the local population go about their business as usual. May Day celebrations begin, children play and the residents of Pripyat, the town built to house the workers at Chernobyl, marvel at the spectacular fire raging at the reactor. After three days, an area the size of England becomes contaminated with radioactive dust, creating a 'zone' of contaminated land. This is the story of the people who dealt with the world's worst nuclear disaster at ground level: the fire-fighters, the soldiers, the 'liquidators' and their families.