In 1957, Britain exploded its first megaton hydrogen bomb - codenamed Operation Grapple X. It was the culmination of an extraordinary scientific project, which against almost insuperable odds turned Britain into a nuclear superpower. Featuring access to the top-secret nuclear research facility at Aldermaston, the programme features interviews with veterans and scientists who took part in the atomic bomb programme, some speaking for the first time, and newly released footage of the British atomic bomb tests.

En 1957, Gran Bretaña detonó su primera bomba de hidrógeno de megatón, llamada Operación Grapple X. Fue la culminación de un proyecto extraordinario en el que los científicos superaron todas las probabilidades para convertir a Gran Bretaña en una superpotencia nuclear.