Mummie sat silent for a long time.
"Remember, children," she said at last, "never do evil that good may come—I can't expect you to understand that—but I can tell you a little story."
"A story!" cried the twins. "Hooray!"
"Once upon a time a town was besieged. It was night, and only the sentinels on the walls were left on guard, and told to give the alarm by clanging a large bell, should the enemy force an attack. There was one sentinel who had never done this work before, and he was given the least important tower to guard. During the night a loud bell clanged out, and a soldier came running along the wall to speak to the new sentinel. 'Do come,' he said, 'we want as many helpers as we can get at once, and there will be plenty of fighting.' The young sentinel longed to go with him, and join the fight, but he remembered his duty in time.
"'I cannot leave this tower,' he said; 'I have had orders to stay and give the alarm should the enemy appear, and the town trusts me to do so.'
"'I believe that you are afraid,' said the soldier as he hurried away.
"And this was the hardest of all, and the sentinel longed to join in the fighting to show that he, too, was no coward, but could fight like a man.
"He stood there, listening to the noise in the distance, to the shouts of the enemy, and the screams of those who were struck down. And as he looked below the walls into the valley beyond he thought that he could distinguish men moving, and while he watched he saw a number of soldiers creeping up to the walls, and one man had even placed his foot on the steps that led up to his tower. Quick as thought, the sentinel seized the rope of the large bell that hung over his head and clanged it again and again.
"In a few minutes the troops were assembled, and, making their way down the steep steps, they charged at the enemy, and followed them into the valley.
"Late on the following evening the soldiers returned, but not all, for many were killed—and they brought back news of a great victory. The enemy was routed and the town saved. So you see, children," said mother gravely, "how much better it is to do what is right. If that young sentinel had left his post, even though it were to help the men in the other tower, the enemy would have climbed up those steps and got into the town. You must try to remember this always. You should have obeyed nurse, and remembered that she was trusting you to do what she had said. It was a kind thought of yours to try to rescue Poor Jane's brother, but obedience to nurse should have come first."