Convinced that his long-time patient Nick Osborn didn't murder his boss, Mark Sloan starts investigating the case himself, supported by a junior doctor and a young female pathologist.

Years after J.R. Ewing lost Ewing Oil and apparently committed suicide, we learn that he is alive and well. He returns to Dallas, and plots what could be his greatest scheme: Bringing his family back together, and regaining control of Ewing Oil from arch-enemy Cliff Barnes. Will he be successful?

Colonel Pete Moore (Glenn Ford) is commander of the Whitney Radar Test Group, which has been experiencing electrical difficulties aboard its aircraft. To ferret out the problem, he sends a four-man crew on Flight 412. Shortly into the test, the jet picks up three blips on radar, and subsequently, two fighters scramble and mysteriously disappear. At this point, Flight 412 is monitored and forced to land by Digger Control, a top-level, military intelligence group that debunks UFO information. The intrepid colonel, kept in the dark about his crew, decides to investigate the matter himself.