Dr. Cal Meacham (Rex Reason), Dr. Ruth Adams (Faith Domergue), and Dr. Steve Carlson (Russel Johnson) are among the scientists chosen to participate in a nuclear research experiment in a remote laboratory facility. Dr. Meacham is an atomic energy specialist who assembled an "interociter" which allowed him to communicate with Exeter (Jeff Morrow), and be invited to advance atomic power to solve the energy crisis.
The research team becomes suspicious of Exeter because of his ignorance of Earth customs and they try to escape. Dr. Carlson is killed and Cal and Ruth fly away but their plane is abducted by a flying saucer. When they reach outer space, the thoughtful Exeter admits he is an alien from planet Metaluna, at war with the evil Zagons. The Metalunans are forced underground because they are bombarded by asteroids from the Zagons.
Exeter explains, "They're concencentrating all their attention on Metaluna. Those flashes of light--they're meteors--hundreds of them! Intense heat is turning Metaluna into a radioactive sun. Temperature must be thousands of degrees by now. A lifeless planet. And yet...yet still serving a useful purpose, I hope. Yes, a sun. Warming the surface of some other world. Giving light to those who may need it. Now, into the converter tubes! Ruth, you take the first tube. You the next."
When they reach Metaluna, the planet is in ruins and The Monitor (Douglas Spencer) reveals that the Metalunans plan to relocate to Earth. He says, "It is indeed typical that you Earth people refuse to believe in the superiority of any world but your own. Children looking into a magnifying glass, imagining the image you see is the image of your own size." The Monitor orders Cal and Ruth into the Thought Transference Chamber to destroy their free will.
Exeter considers the planned invasion to be immoral and decides to help the Earthlings escape. They are attacked by a huge "Mute-Ant" bug-like monster, which Cal overpowers after it wounds Exeter. They journey back to Earth. Exeter allows Cal and Ruth to fly away in their plane, but he and his saucer crash into the sea.
The cast also includes: Lance Fuller (Brack), Robert Nichols (Joe Wilson), Karl Ludwig Lindt (Dr. Adolph Engelborg), Spencer Chan (Dr. Hu Ling Tang), Regis Parton (Mutant), Lizalotta Valesca (Dr. Marie Pitchener), Robert Williams (Webb), Orangey (Neutron), Charlotte Lander, Jack Byron, Richard Deacon, Coleman Francis, Marc Hamilton, Edwad Hearn, Edward Ingram, Onal Soule, and Les Spears. Music is by Henry Mancini, Hans J. Salter, and Herman Stein. The screenplay is by Franklin Coen. Bud Westmore did the makeup. Joseph M. Newman initially directed but was replaced with uncredited Jack Arnold.
THIS ISLAND EARTH is a classic sci-fi space opera based on Raymond F. Murrow's 1938 story, "The Alien Machine". It has futuristic designs, very good makeup, and excellent visual effects for its era, which took 2 1/2 years to make by Clifford Stine and Stanley Horsley. The drama is good, acting is second-rate, and the plot is sometimes stilted, plodding and overcomplicated. Film critic David Kehr wrote it "remains among the most poetic and dreamlike of 50's fantasies." This exciting intergalactic adventure is spoofed in MYSTERY SCIENCE THEATER 3000: THE MOVIE (1996).
