A test explosion of the first atomic Plutonium is planned at a military site in Desert Rock exercises. When it does not detonate as expected, Lt. Colonel Glenn Manning (Glenn Langan) receives orders to keep his men in the protective trench. Moments later, an unidentified small civilian aircraft crash-lands near the bomb site, and Glenn runs into the detonation area to rescue the pilot. Once in the detonation area, the bomb goes off, and Glenn is caught in the radiation.