Before watching the movie:
Here is a sci-fi B-movie. B-movies can be fun. Very few B-movies are legendary enough to be well-known. This is not one of them.
Apparently John Agar is a big name of B-movies, but I don’t recognize him. Mainly because I’m not steeped in B-movies. But they are fun.
After watching the movie:
Dr. Adam Penner resigns from atomic research in protest of the violent direction the science is being pushed in when his colleague is killed in a laboratory accident. His friend’s corpse is subsequently possessed by an invisible alien who warns him that as human research into atomic warfare and space travel has made them a threat to the aliens’ intergalactic regime, Earth has one day to surrender to their might or they will use the bodies of the dead to kill all the living humans. Penner asks Dr. Lamont, whose reputation with the Pentagon is not tarnished by protest, to bring them the warning, but it goes over as one might expect. Following a more believable ultimatum addressed directly to large crowds, Earth governments decide to resist the invasion, and the world is engulfed in fire and blood. Penner, Lamont, Penner’s daughter Phyllis, and Major Jay are ensconced in a hidden bunker and have to science their way into discovering any weakness that might be used against the invisible, intangible, invulnerable invaders.
I get the sense that Phyllis is mainly there because a movie like this needs to have a woman to romance and imperil, but there isn’t much of either happening. There’s a suggestion of a love triangle with Lamont and Jay, but nothing happens. She’s in danger in the besieged bunker, but no more than the others. She’s not going out to try to capture the aliens, so she’s really not very imperiled at all. She just doesn’t seem to do much of anything. At one point, it’s commented that they don’t need her unless they need something written down. So she’s not exactly dead weight, but she is an inactive ingredient.
The movie drops a hasty moral about “maybe the nations of the world can work together peacefully”, but that’s not a theme that seems at all developed. We see an entirely American effort, and once the day is saved by science, the answer is sent around the world and the aliens are repelled between scenes. The closest it gets to talking about putting aside differences for the common good is when there’s an argument about whether they should surrender or not, which ultimately leads them to stumble upon the solution. The real message is that individual human (American) ingenuity will ultimately defeat advanced alien (foreign) threats.
This is at least somewhat less cheesy than Plan 9 From Outer Space, but rather than playing with flying saucers and not-really-vampires and not really going anywhere, the aliens who reanimate our dead to warn us to stop messing around with atomic weapons or they’ll have to annihilate us actually get on with annihilating us, and there’s some more excitement as a result. However, I’ll go with ludicrously campy dialogue over the wooden, no-nonsense storytelling on display here. Neither has a point, but at least the other is a lot of fun to mock.