United States Air Force Colonel Pete Moore (Glenn Ford) is the commander of the Whitney Air Force Base 458th Radar Test Group, which has been experiencing electrical difficulties aboard its aircraft. To find the problem, he sends a four-man crew on Flight 412, with Captain Bishop (David Soul) as commander. Lt Podryski (Greg Mullavey), Capt Riggs (Robert F. Lyons), and Lt Ferguson (Stanley Bennett Clay) are Bishop's crew. Shortly into the test, the Grumman Gulfstream II jet, a small twin-engine VIP transport, picks up three blips on radar. Subsequently, two fighters scramble to investigate and mysteriously disappear.