In the intervals of their quarreling, which continued intermittently all the while she was there, Mary V quizzed him about his ambition to fly.

Did he really intend to learn "the game"?
Had he ever been up in a flying machine?
It seemed that Johnny had made two ecstatic trips into the air--for a price--at the San Francisco Fair the fall before, and that his imagination had never quite felt solid ground under it since! Where--or how--could he learn?
If she were secretly trying to inveigle Johnny into showing her his new Correspondence Course, so that she might be a gleeful witness when he discovered her additions and revisions, she must have been a greatly disappointed young woman.

For Johnny that day demonstrated how well he could keep a secret.

He warmed to her apparent interest in his chosen profession, but he did not once hint at the lessons, and kept rigidly to generalities.
Mary V mentally called him sly and deceitful, and started another quarrel over nothing.

While this particular battle was raging, there came an interruption which Mary V first considered sinister, then peculiar, and at last, after much cogitation, extremely suspicious and a further evidence of Johnny's slyness.
A Mexican rode up to the doorway, coming from the east.