With millions of people at risk after the Chernobyl explosion, nuclear physicist Ulana Khomyuk makes a desperate attempt to reach renowned inorganic chemist Valery Legasov to warn him about the threat of a second explosion.
On 26th April 1986, an explosion at the Chernobyl Nuclear Power Plant in the Union of Soviet Socialist Republics became one of the world's worst man-made catastrophes.