pleading in the name of a great army of sick children,
that Nan would not desert their cause; that she would go on, as she
had promised them, with her search for ways that should restore their
vigor and increase their fitness to take up the work of the world. And
yet, a home and children of one's very own,--the doctor, who had held
and lost this long ago, felt powerless to decide the future of the
young heart which was so dear to him.

Nan saw the familiar old horse and carriage waiting behind the
station, and did not fail to notice that the doctor had driven to meet
her himself. He almost always did, but her very anxiety to see him
again had made her doubtful. The train had hardly stopped before she
was standing on the platform and had hastily dropped her checks into
the hand of the nearest idle boy, who looked at them doubtfully, as if
he hardly dared to hope that he had been mistaken for the hackman. She
came quickly to the side of the carriage; the doctor could not look at
her, for the horse had made believe that some excitement was
necessary, and was making it difficult for the welcome passenger to
put her foot on the step. It was all over in a minute. Nan sprang to
the doctor's side and away they went down the road. He had caught a
glimpse of her shining eyes and eager face as she had hurried toward
him, and had said, "Well done!" in a most cheerful and every-day
fashion, and then for a minute there was silence.

"Oh, it is so good to get home," said the girl, and her companion
turned toward her; he could not wait to hear her story.

"Yes," said Nan, "it is just as well to tell you now. Do you remember
you used to say to me when I was a little girl, 'If you know your
duty, don't mind the best of reasons for not doing it'?" And the
doctor nodded. "I never thought that this reason would come to me for
not being a doctor," she went on, "and at first I was afraid I should
be conquered, though it was myself who fought myself. But it came to
me clearer than ever after a while. I think I could have been fonder
of some one than most people are of those whom they marry, but the
more I cared for him the less I could give him only part of myself; I
knew that was not right. Now that I can look back at it all I am so
glad to have had those days; I shall work better all my life for
having been able to make myself so perfectly sure that I know my way."

The unconsidered factor had asserted itself in the doctor's favor. He
g