John Doubler believes the future of the human race depends on colonizing Mars. To prove his point, he abducts his wife Grannie and embarks on a voyage to the red planet in a rocket ship he built himself. After three months in the windowless space capsule, Grannie is ready to kill. She's convinced he is crazy and tries to escape. He is afraid that Grannie has gone mad and tries to subdue her. One is right as revealed in a surprise ending.