With a passion for aviation design and engineering, wealthy oilman John Ridgefield (Ralph Richardson) is determined to break the sound barrier with the aircraft company he owns. He has already lost his son in the pursuit, and his daughter, Susan (Ann Todd), resents her father even more when he chooses her husband, World War II pilot Tony Garthwaite (Nigel Patrick), to be one of the test pilots. Yet Ridgefield stands resolute in the name of scientific progress.