Oil! by Upton Sinclair

Bunny went back to Beach City, to face a trial of the same sort. Grandma did not cry out or faint, she just went up to her studio-room and locked the door and did not appear, even for meals. When Bunny was ready to go, he went and knocked on the door, and Grandma let him into her laboratory of paints and oils and high art. Her face was drawn but grim, and only her withered red eyelids gave her away. "Little boy," she said -- he was still that to her, he would never grow up -- "little boy, you are a victim of the old men's crimes. That means nothing to you now, but remember it, and some day, long after I'm gone, you'll understand."

She kissed him without a sound, and he stole out, with tears running down his cheeks, and feeling somehow as if he himself were committing a crime. He felt still more that way when, a week later, he received a telegram saying that Grandmother Ross had been found dead in bed. He got a three day leave to come home and attend the funeral, and had to say his goodbyes to the rest of the family all over again.