This film describes the nature of the declassified nuclear testing films released to the public in the late 1990s. These films were classified Top Secret for many years, but are important for their historical context. While most Americans were aware that nuclear testing was taking place, very few were aware of the size and scope of the testing program. Small snippets of these films were released to the public, and on a very few tests the press were included as spectators (there was even one test shown live on television), but the sheer magnitude of the testing program remained a secret.

Part 2 of a 4 part series of films of Operation Hardtack. Prior to Operation Hardtack, the highest nuclear test had been conducted at 36,000 feet at the Nevada Test Site. Since the development of ICBMs as a delivery method for nuclear weapons had been developed, the use of nuclear warheads to intercept and destroy incoming ICBM warheads was being considered as a defense. Since the effects of high altitude detonations and possible kill mechanisms were unknown, the high altitude tests of Operation Hardtack were planned to gather data on nuclear detonations at altitude. One interesting thing about this film, is that test data was gathered on X-ray induced mechanical shock. The fact that electromagnetic radiation striking an object imparts a mechanical pressure on that object is known, but the effect is usually so slight that it's difficult to measure, and often ignored. For X-rays to do this is somewhat counterintuitive (X-rays tend to pass through most materials), and to actually cause mechanical stresses to the breaking point of an object, the X-ray flux must be almost unimaginably powerful. Some of this kinetic energy is probably a result of the X-rays being absorbed and causing thermal ablation of the material. Another interesting thing in this film is the changes in light emission characteristics as altitude increases. The "double pulse" of light from low altitude bursts is missing at higher altitudes, and bursts in between share characteristics of both.