The Creeping Terror

While driving along a highway in fictional Angel County, Martin Gordon and his wife Brett meet Martin's uncle, Sheriff Ben. They decide to investigate the reported crash site together. At the location they discover an abandoned forest ranger's truck, the ranger's hat, and an alien spacecraft that resembles a camping trailer. A large, slow-moving slug-like creature had already emerged from the craft and departed prior to their arrival.

Believing the ranger might be inside, Ben crawls underneath the craft to breach it. He disappears from view for a moment as the others watch anxiously. Shortly after, loud screams and lion-like growls emanate from within, prompting Martin to radio for help.

In response to Martin's call for assistance, a special unit of military troops commanded by Col. James Caldwell arrives in a light-duty civilian truck at the crash site. Two troops enter the craft and report back that a large tethered creature is inside. The team prepares to coordinate with Dr. Bradford as the investigation begins to take shape.

The next day, Dr. Bradford, the world's leading authority on space emissions, arrives to direct the ongoing investigation. He orders examinations of the tethered creature and the spacecraft's analog devices. The inquiry begins in earnest as tissue samples are collected and analyzed.

As the investigation proceeds, the departed creature stalks the countryside. Despite its awkward and slow pace, it relentlessly moves and preys on bystanders. It first claims a bikini-clad girl, then a housewife hanging laundry.

The creature continues its rampage, attacking a man and his grandson, then picnickers at a hootenanny, and later teenagers and couples at lovers' lane. Public fear grows as authorities struggle to contain it. The monster's pattern shows it moves slowly but lethally.

Caldwell orders the troops to attack the creature, insisting they should capture it alive if possible. The soldiers form up and advance as a unit, firing their small-caliber weapons. The assault proves ineffective, and all but two of the troops are devoured.

Caldwell throws a grenade that finally kills the creature, ending its immediate threat. Bradford briefly examines the creature's tissue before hurrying back to the spacecraft and triggering an explosion there. The blast is powerful but does not damage the craft or its instrumentation, and the tethered creature is able to exit.

As the tethered creature moves to devour Bradford, it is killed in a collision with Martin's arriving police car. Bradford explains to Martin and Brett that the creatures were mobile laboratories designed to consume humans, analyze their bodies chemically to detect weaknesses, and transmit the information back to space. He adds that the home planet might not exist anymore, saying that only God knows for sure.

Bradford's explanation reveals the true purpose of the aliens and the risks they pose, leaving the immediate threat behind but the danger of the transmissions unresolved. Martin fails to destroy the spacecraft's transmitter equipment, meaning its signals could continue to reach space. The moment ends with the couple facing an uncertain future.

Bradford's final revelations linger as authorities consider the wider implications of the alien technology. The transmitter's persistence suggests Earth could still be watched or visited by unknown forces. The scene hints that the danger may extend beyond the immediate encounter.

The film closes with a sense of cosmic mystery, repeating that 'only God knows for sure.' Martin and Brett look toward the horizon, aware that the threat may not be over and that more questions remain about the aliens and their network. The unresolved transmitter leaves the audience with an open-ended threat.