Rudi Graf has helped create the world’s most sophisticated weapon: the V2 ballistic missile.
In a desperate gamble to avoid defeat in the winter of 1944, Hitler orders ten thousand to be built and Rudi is tasked with firing these weapons at London. Kay Caton-Walsh is an officer in the Women’s Auxiliary Air Force and a survivor of a V2 strike. As the rockets devastate London, she joins a unit of WAAFs on a mission to locate and destroy the launch sites. Rudi and Kay fight their grim, invisible war – until one final explosion of violence causes their destinies to collide.