Dubbed the Silver Angel by the press, the BR-101 Rapier is a state of the art supersonic strike aircraft being developed for the Royal Air Force in the shadow of the Cold War. The Rapier is already under threat as over running costs are forcing the newly formed British government to scrap the aircraft in favour of a rival American design.
Inside the assembly hangar at Brinton Aviation, a young apprentice aircraft designer is found dead under the second prototype so on behalf of the fiancé of the deceased man, ex MI5 officer Alex Swan and his colleague former Scotland Yard detective Arthur Gable, investigate the incident exposing a plot that could threaten the lives of thousands of innocent spectators; when the Silver Angel makes its debut appearance at the 1965 SBAC show.