
An architect is convinced there are aliens in the world.

Vincent is accused of murder after an explosion kills a senator seconds after he delivered a warning about an alien's presence.

A communist delegate calls for Vincent's help when an alien intruder is caught inside the building; guests Dana Wynter, Fritz Weaver.

A pretty psychologist (Carol Lynley) offers Vincent a chance to escape when extraterrestrials capture him for interrogation.

Aliens threaten Earth with severe recrimination if Vincent does not release a high-ranking alien hostage (Alfred Ryder).