Based on a novel by Karel Capek, a prominent Czech writer of the early 20th century, who coined the word robot for his play R.U.R., the story revolves around a discovery of Krakatit-a powerful explosive by Prokop, the main character of the movie. After an accidental explosion in the lab, exhausted Prokop slips in and out of dream-like hallucinations. He later realises that in his altered state of consciousness he had given the formula for making Krakatit to one of his colleagues, and he tries to stop its spread before it is too late. But there are too many dark, powerful forces interested in the ultimate explosive.