Scooby, Shaggy and the gang are driving down an old country road and are running out of gas and have to stop soon. They park at an old farmhouse and talk to an old farmer who at first mistakes the gang for reporters. The gang explains their situation and the man says that the reporters have been bothering him because a spooky spacecraft and an alien has been haunting an abandoned air-field adjacent to the farm. After getting gas, Fred, Daphne, Velma, Shaggy and Scooby realize they have a mystery on their hands and they follow a strange air-craft flying and follow it to the abandoned air field. They find a running generator and Scooby and Shaggy have a run-in with a creepy alien-type creature in a space suit that laughs hysterically (in a very memorable way). Fred and the girls search for clues and Fred gets caught by a hook and is dangling in the air. They rescue him and then the space ghost arrives and the kids flee and Shaggy and Scooby arrive at the mess hall where they find fresh food, but the space alien comes again and chases them away. The gang then finds a Jeep that runs by itself and an army of the space alien ghosts just materializes. Then, the biggest clue is when Shaggy and Scooby head into the air tower and find a movie projector and tape recorder.
The culprit, after chasing Scooby and Shaggy, goes into the wind tunnel by accident and gets his costume blown off.
The crook happened to be the old farmer's neighbor, Henry Bascombe. He was trying to exploit the land for money after he heard that the air-field was re-opening again. The army of ghosts was just a bunch of stuffed dummies, and the Jeep that runs by itself was just remote control. The spooky laugh was played over the loudspeakers, and the spacecraft was a movie projector.
When Fred finds a newspaper article hidden in a barrel, Daphne says to look at an article that has been circled. When the paper is in view, there is no circle.
Perhaps the biggest oddity of this episdode is the existence of all the functional equipment on the abandoned air field. Regardless of the field being public or military, wouldn't every piece of working equipment be stripped when they shut the field down?
Given the cramped space, there probably shouldn't have been a life raft in the cramped cockpit of an aeroplane, as it seems to break Federal Air Regulations pertaining to Life Rafts- furthermore, it was not tethered to the plane.