Lesson for Today

With the world destroyed around them, Helen wondered why she and Robbie were still left alive. There must be a reason—and of course, there was....
While we remain in our invisible space-ship, the inhabitants of this world cannot see us. Prepare to take notes now in preparation for your final exam on the subject Alien Creatures and Their Actions in Given Situations. Notice below us the female of the dominant Species. She is with her child....
Clutching Robbie in her arms and holding him tight, Helen Thompson sat down wearily on the ground. The cold and dampness was all around her, boring through the thin cotton dress she wore. Her flesh was cold and her dark brown hair hung in ringlets over her forehead. She wore no shoes. She had lost them miles back, near the ruins at the edge of Chicago. Her feet were blistered and bleeding, numb now from the cold of early morning.
Carefully she put her sleeping child on the ground for a moment as she rubbed her feet trying to restore circulation. Slowly feeling came back and then she flinched as pain shot up her legs.
She picked up the child and started again, heading westward.
See the way she tries to protect her young, cradling it in her arms, shielding it from the coldness with her own body.
Now the sun was higher in the sky. The cold was gone now. But still there was something surrounding her, enclosing her, almost like a prison wall. Yet she could not see it.
Radiation!
Radiation from the long exploded bombs. It poisoned the air. It killed all vegetation. It killed all the animals. All except the two of them, the woman and her child. It had spared them. Not because it wanted to, but because it had to. Vaguely she remembered....
She and Robbie had been sitting in a Chicago park when the first bomb dropped. It fell quite near them, about three miles away. She remembered the bright blinding flash. Above them the branch of a tree cracked. It fell to a point twenty feet over their heads. Then it stopped. It was as if some force held it back. The force, whatever it was, also held back the heat. But it didn't stop her from fainting in terror.