What is the summary of "If I Forget Thee, O Earth?"

"If I Forget Thee, Oh Earth" is a short story by Arthur C. Clarke. This story can be split into two distinct portions: the exposition and the didactic. In the beginning of the story, the exposition, hints about the location and context are given, but nothing is explicitly told to the reader. Once the father begins speaking, the didactic section begins, in which the author clearly explains everything to both Marvin and the reader. 

• Marvin is walking with his father through a compound with different sections, and he is thrilled to realize that they are going outside.


• Marvin and his father get into a car, and after the atmosphere is depressurized, they drive out of the compound.


• Marvin sees a landscape that is cold, dry, and colorless. The sky is black but filled with stars, which he contemplates for the first time. 


• Marvin and his father drive on, quickly losing sight of their home, which Marvin refers to as the Colony, though still occasionally seeing signs of humanity.


• They drive on through an exhilarating landscape, through the nightfall. And then, where it should be all dark, Marvin sees a beautiful white light.


• Marvin's father stops the car, and Marvin looks out at a planet, which he describes as silvery bright and beautiful. Wondering why they cannot return, he thinks back to Armageddon, and describes the poisonous glow in parts of the planet meant to be dark. 


• Marvin's father begins to tell him the story of the destruction of Earth, the source of which is unknown. Only the Colony was spared because of its isolation, and its population has worked desperately to survive. 


• Marvin realizes that the goal of the Colony, his life, and the life of his progeny will be to return to Earth. He vows to return to this site with his own son.