This novel is written from a series of detailed story outlines Alistair MacLean was commissioned to write by an American film company in 1977. A deadly cargo of plutonium-IV is secreted in a freight car travelling through Europe. The United Nations Anti-Crime Organization mount an operation to discover how the plutonium was stolen. Their agents find themselves up against a conspiracy of interests including a sinister arms dealer and a highly-placed business magnate. Of the six kegs discovered, one contains a substance that could have catastrophic results for the whole world for generations to come.