Dr. Cal Meacham (Rex Reason), nuclear physicist, dashing pilot, and media darling, is flying home from a conference in his personal jet when a sudden engine failure sends him hurtling towards the ground, only for him to be saved at the last minute when a green glow surrounds the vessel and helps it land safely. The weirdness continues at his lab, when Meacham and his assistant Joe Wilson (Robert Nichols) ponder over a strange electrical capacitor they received that is obviously more advanced than any human technology. Placing another order from the mysterious company that sent it results in a huge shipment of arcane doodads and a complex set of instructions. With the help of a montage, the two successfully assemble an "interocitor," and receive a transmission from an orange-skinned, white-haired, dimple-foreheaded, definitely-not-an-alien named Exeter (Jeff Morrow). He congratulates Meacham — apparently the interocitor is a test he and his colleagues use to recruit scientists for a special project — and invites Meacham to join him.
After a brief ride on a windowless, unmanned plane, Meacham joins Exeter and a host of other scientists at a stately mansion, where Meacham is reunited with Dr. Ruth Adams (Faith Domergue), who doesn't seem to remember the romantic time the two spent together despite Meacham's insistence (in a later scene, she reveals that she was actually testing him to see if he's on the level). Eventually Ruth and Meacham, along with their colleague Steve Carlson (Russell Johnson—yes, The Professor himself), grow suspicious about the weird white-haired fellows running the place, and of the fact that all the scientists there are specialists in extracting nuclear power, but not utilizing it. The three of them make a break for it, only for their hosts to blow up the mansion, abduct Meacham and Ruth in a flying saucer, and kill Steve, making him a bit character probably not worth mentioning in a summary of the movie.
The Earthlings' suspicions confirmed, Exeter calls for a truce as they are en route to his homeworld of Metaluna. He explains that their planet is under siege from hostile aliens and is protected by an energy field, but said shield requires gigantic quantities of nuclear power to operate, thus prompting their interest in Earth. Once on Metaluna, Exeter brings Meacham and Ruth before the Monitor who runs Metalunan society, who ignores Exeter's protests and sentences the Earthlings to the Thought Transference Chamber to make them more willing partners. Exeter rebels and helps the Earthlings escape, though he is grievously injured by a rogue Mutant worker creature. The three of them hijack a saucer to return to Earth, only to be confronted by the same Mutant, who menaces Ruth for a bit before keeling over. Once back on Earth, a dying Exeter literally drops Meacham and Ruth off before sending his flaming saucer into the ocean.
This Island Earth returned to the big screen 41 years later when it was riffed by the Satellite of Love crew in Mystery Science Theater 3000: The Movie.
This Island Earth film provides examples of:note
- All for Nothing: Exeter's plans to use Earth to save Metaluna amount to nothing. The planet is destroyed, and Exeter quickly follows his people into extinction.
- Anti-Villain: Exeter, at the worst, is this. He avoids being a Well-Intentioned Extremist mainly because he refuses to go to such extremes out of respect for those he is exploiting, even as he faces pressure from both overlings and underlings to do so, and he wishes no harm upon the Earth or its inhabitants. He later performs a full Heel–Face Turn when he can no longer rationalize his leaders' increasingly aggressive intentions.Exeter: What happened back there [the death of all the scientists] was beyond my control.
Meacham: What happened was mass murder!
Exeter: We're not all masters of our souls, Meacham.
Meacham: That's a nice phrase, coming from you.
Exeter: I learned it on Earth. - Artistic License – Physics: Lots of it. Some examples:
- The laboratory cat is called Neutron "because he's so positive". These people are meant to be nuclear physicists and yet they can't tell the difference between a neutron, which has no electric charge, and a positively-charged proton. (This could have been dry scientist humor, but it's not quite played that way.)
- The Earth is surrounded by a "heat barrier" which causes the saucer's hull to glow red-hot, flame and smoke. Note this is well after they have left Earth's atmosphere, and only occurs when leaving Earth.
- A similar effect occurs before Exeter crashes into the sea, but again, this is well after re-entry since Cal and Ruth have already disembarked.
- Magnetic clamps hold flesh and blood fast.
- The Zagon planet used to be a comet.
- The planet Metaluna is transformed into a sun by meteorite bombardment. Exeter claims that this new sun may warm other worlds some day, though it's not clear where he expects them to come from in defiance of the laws of orbital mechanics.
- As mentioned below, a radioactive sun.
- Conversion is a process necessary to allow a human or alien to transition from Earth to Metaluna air pressure and back. Yet converted and unconverted crew are exposed to the same ship air pressure without ill effect. The mutant does not fare so well.
- Possibly we are meant to assume that the ship's atmosphere changes during the conversion process, although this is never made clear.
- Cal's research is into how to turn lead into uranium.
- Cal is introduced as an electronics expert, but by the time he joins Exeter's team he's a nuclear physicist, and finds it odd that Exeter isn't recruiting electronics experts.
- Artistic License – Space: Earth is depicted as cloud-free when seen from space. This is partly due to using the same Earth model used for the production studio logo AND the fact that this movie was made in 1954, three years before the first satellites went up and sent back pictures.
- Attack Its Weak Point: The big-brained Mutants are unsurprisingly vulnerable to blunt trauma to the head.
- Bittersweet Ending: Sure, the Earth is saved, but the entire Metalunan race is wiped out by the Zagons. The Metalunans weren't really evil, just desperate. And the movie ends with Exeter's ship crashing into the ocean in flames. Oh, and the Zagons are still out there, and it's an easy guess that they will inevitably take a malevolent interest in Earth, too.
- Bluff the Imposter: A variation; Cal Meacham isn't an imposter, and Ruth doesn't think he is, but when she greets him at the airfield she fakes mis-remembering their last meeting, forcing him to fill in the details so she can be sure he hasn't been mind-zonked.
- Cataclysm Climax: Exeter and the humans escape Metaluna just in time to watch it go ker-blooey.
- Chekhov's Skill: Seemingly the only justification for the film's opening scene of Cal Meacham flying himself cross-country in his own personal jet, rather than taking a commercial airliner, is to establish his piloting skills for later.
- Chewing the Scenery: Exeter's unnecessarily-dramatic commands to the Mutant. Possibly justified as his grand pronouncements would normally work on the subservient Mutants, but this particular Mutant was malfunctioning.Exeter: Stand back! I command you, STAND BACK!Mike: Acting!
- Colony Drop: The Zagon direct a fierce bombardment of meteorites at Metaluna, which eventually destroy the planet and turns it into a "radioactive sun"...somehow.
- Cool Chair: Averted and played straight. The captain has a cool chair that bears some resemblance to a tricked-out chrome toilet, but in other ways Metalunan furniture technology is light-years behind Earth's. The "chairs" Cal and Ruth use are basically upright slabs with arm rests and a small ledge for the butt. (The lead actress revealed that their jumpsuits were so impossibly restricting that the chairs were the only way they could comfortably sit for extended periods.)
- Computer Equals Tapedrive: Completely justified. This was made in the 50's, remember.
- Cosmic Deadline: The Monitor (Metaluna's President Evil) reveals that the Metalunans plan to relocate to Earth. Less than an hour later (in-universe time) Metaluna is destroyed, the mass exodus apparently never even getting off the ground.
- Crapsack World: Thanks to the constant bombardment of Metaluna.note
- Determinator: The Mutant that attacks the protagonists as they flee Metaluna. It gets injured as its world is destroyed, yet manages to wound Exeter before being bludgeoned by Cal. It then crawls onboard their ship as they take-off and continues attacking until it keels over, even though its masters are dead and it's suffering brain damage and losing oxygen.
- Dissonant Serenity: Dr. Engelborg was out taking his constitutional walk when the Metalunans begin to destroy their base before departing for home. He runs into Cal, Ruth, and Steve as they try to escape, and he merrily waves to them all, apparently oblivious to all of the destruction and explosions that have been happening all around him. Not surprisingly, he's almost immediately killed by another explosion. This may be to suggest that Engelborg had been put into the Thought Transformer.
- Evil Is Petty: The leader of Metaluna orders Cal and Ruth's brains to be wiped minutes before Metaluna is about to be destroyed.
- Failed a Spot Check: A rather bizarre example, in that Ruth and Carlson have detailed sketches of the "peculiar indentation" in Exeter's forehead but somehow have failed to notice that Exeter's forehead is seven inches high.
- Forehead of Doom: The Metalunans haz em. Their tall white pompadours only add to it.
- Futile Control Fiddling: Cal Mechem buzzes a flight tower, but his little stunt causes a flame out, killing his jet’s power. Before he’s unknowingly rescued by the Metalunans, he's seen fighting with the control stick.
- Green Rocks: Interocitors can be used as communication devices, viewscreens, autopilots, road-layers, and of course, death rays.
- Hard-Work Montage: When assembling the interocitor.Crow: Industry, science, and technology!
Tom Servo: Big men putting screwdrivers into things! Turning them! And adjusting them! - Hemisphere Bias: North America is quite prominent as the interstellar travelers return home.
- Heroic Sacrifice: Steve Carlson bought Cal and Ruth time by making the aliens think they blew up the car killing all three.
- It's possible that was his intention, but it's also likely the aliens waited for Cal and Ruth to leave the car before killing the expendable Carlson. Cal and Ruth were then allowed to reach the aircraft, in which they were easily abducted.
- Hollywood Darkness: Our heroes attempt to sneak away from the aliens "under cover of afternoon."
- Homage: This Island Earth has popped up in the background of works from E.T. the Extra-Terrestrial to Watchmen, while the interocitor makes cameos in works as diverse as UHF and Ciaphas Cain. Joe Dante loved the film, so it appears in Explorers, too. The Mutant also appears in Looney Tunes: Back in Action and in the opening credits for Ernest Scared Stupid. In a special foreword written for the hardcover edition of The Kree/Skrull War, Roy Thomas stated that the original novel version of This Island Earth was a major influence on the story.
- Hugh Mann: During dinner, Exeter refers to Mozart as "your composer". Initially, Exeter doesn't even recognize the name.
- Hyper-Competent Sidekick: Joe Wilson is a highly competent assistant. Yes, he's already ordered replacement condensers, AND tested one of the weird beads that came in their place AND set up another bead ready for Cal to test himself.
- Insectoid Aliens: The Metaluna Mutants, humanoid crustacean/insect-like creatures genetically engineered by the more humanoid Metalunans to serve them.
- Invading Refugees: At the last minute, the Metalunans plot to escape the Zagons by fleeing to Earth (and enslaving humanity in the process). Metaluna is destroyed before the evacuation can even begin.
- It Runs on Nonsensoleum: Pretty much anything that Exeter says when he attempts to explain anything sciencey. Particularly the Mutant "Similar to your Earth insects, but larger of course," ignoring all the other clear differences. He also says that the clamps are magnetized and hold flesh and blood fast.
- Jerkass: Cal Meacham comes off as a bit of a smug jerk. He jokingly tells the reporters he "hopes you taxpayers don't mind" paying for his plane, says his lab assistant's wife would gain twenty pounds if she had access to the tools in the alien catalog, and keeps reminding Love Interest Ruth about how much of a sissy she is.
- Last of His Kind: Exeter and one of the Mutants are the only Metalunans shown escaping the planet's devastation. Neither of them live long after.
- Mind Control:
- The Thought Transformer is planned to be used when the Metalunans relocate to Earth.
- Presumably it has been used on the scientists at the plantation as well. The way Ruth and Carlson talk, it's entirely possible that they and Meacham are the only three who haven't been mind-controlled.
- Monster Misogyny: The Mutant's last appearance has it lumbering after Ruth while Cal and Exeter watch helplessly from The Tubes.
- Mundane Made Awesome: The dramatic score accompanying the alien viewscreen returning to normal view.
- My Brain Is Big: The oddly-skulled Metalunans probably qualify, as do the Mutants, whose heads are at least 50% exposed brains.
- Named After Their Planet: The Metaluans get their name from their homeworld which is called Metaluna.
- Non-Action Guy: Cal Meacham's most dramatic action is socking Exeter as they try to escape Metaluna. He also bonks an alien mutant on the head with a fire extinguisher, thus saving Exeter. For the rest of the movie he's either being led around by aliens or trying to flee them.
- Pinball Protagonist: One issue with this story is that Cal, while not an unlikable character, does almost nothing of consequence. He doesn't save any of the human scientists. He doesn't save Metaluna from its fate, or even bring back any useful knowledge to Earth. He doesn't save Ruth from the Mutant, since it just shambled after the unbelievably clumsy woman until it died. He was basically a tourist until he saved Exeter from the Mutant, even though he couldn't stop Exeter from being mortally wounded, and he didn't even finish the Mutant off or close the doors to the ship before it came aboard.
- Planet Looters: Initially, the Metalunans only want our uranium so they can maintain the forcefield protecting their planet. But when their enemies attack before this is completed, they decide to relocate to Earth.
- Pragmatic Villainy: Both this and being Intrigued by Humanity is what makes Exeter resist brainwashing humans despite the wishes of his superiors. While this is mostly guided by his sympathy to humanity, he also states an argument that humans put through the Thought Transformer have their mental capacities (especially creativity) reduced for the sake of keeping them compliant, and this would do nothing but hinder direly needed scientific advancement.
- Rubber-Forehead Aliens: The Metalulans look exactly like humans with the exception of having larger foreheads.
- Same Language Dub: During the approach to Metaluna, a deep voice reports as if over a powerful speaker system. It is disconcerting to realise that the voice is apparently coming from the pilot who's sat right behind the lead characters, and whose lip movements do not remotely sync with the announcements.
- Selective Magnetism: The grips used by those handles for The Tubes are magnetized to keep occupants still.
- Small Universe After All: The book has the friendly aliens agreeing to pull their forces out of "this galaxy."
- There Is No Kill Like Overkill: The Zagons want to exterminate the Metalunans, and their chosen method is fiercely bombarding Metaluna with meteorites. In the end, the Zagons succeed in destroying the entire planet.
- Travel Montage: Two - one when Cal returns to the air force base from Washington DC at the beginning, and another as he's led to Exeter's compound from the base.
- Underground Alien Civilization: The Metalunans live underground as the surface of their world, called Metaluna, is a barren wasteland that is being constantly bombard by meteors deployed by another species called the Zagon who the Metalulans are at war with. The only thing stopping the Zagon from wiping out the underground cities is a planetary energy barrier the Metalunans created. The plot of this film is caused by the fact the barrier requires Uranium to power it and the Metalunans are running out, which is why they sent some of their own to Earth to both find more Uranium and to find nuclear scientists to help before the Zagons break through and destroy Metaluna once and for all.