Gatewood, more excited and uncomfortable than he had ever been in all his life, watched Keen intently.

“Too bad, too bad,” muttered the Tracer to himself.  “The child needs the encouragement.  It meant a thousand dollars to her—­” He shrugged his shoulders, looked up, and, as though rather surprised to see Gatewood still there, smiled an impersonal smile and offered his hand in adieu.  Gatewood winced.

“Could I—­I see Miss Southerland?” he asked.

“I am afraid not.  She is at this moment following my instructions to—­but that cannot interest you now—­”

“Yes, it does!—­if you don’t mind.  Where is she?  I—­I’ll take a look at the person she discovered; I will, really.”

“Why, it’s only this:  I suspected that you might identify a person whom I had reason to believe was to be found every morning riding in the Park.  So Miss Southerland has been riding there every day.  Yesterday she came here, greatly excited—­”

“Yes—­yes—­go on!”

Keen gazed dreamily at the sunny window.  “She thought she had found your—­er—­the person.  So I said you would meet her on the bridle path, near—­but that’s of no interest now—­”

“Near where?” demanded Gatewood, suppressing inexplicable excitement.  And as Keen said nothing:  “I’ll go; I want to go, I really do!  Can’t—­can’t a fellow change his mind?  Oh, I know you think I’m a lunatic, and there’s plenty of reason, too!”

Keen studied him calmly.  “Yes, plenty of reason, plenty of reason, Mr. Gatewood.  But do you suppose you are the only one?  I know another who was perfectly sane two weeks ago.”

The young man waited impatiently; the Tracer paced the room, gray head bent, delicate, wrinkled hands clasped loosely behind his bent back.

“You have horses at the Whip and Spur Club,” he said abruptly.  “Suppose you ride out and see how close Miss Southerland has come to solving our problem.”

Gatewood seized the offered hand and wrung it with a fervor out of all reason; and it is curious that the Tracer of Lost Persons did not appear to be astonished.

“You’re rather impetuous—­like your father,” he said slowly.  “I knew him; so I’ve ventured to trust his son—­even when I heard how aimlessly he was living his life.  Mr. Gatewood!  May I ask you something—­as an old friend of your father?”

The young man nodded, subdued, perplexed, scarcely understanding.

“It’s only this:  If you do find the woman you could love—­in the Park—­to-day—­come back to me some day and let me tell you all those foolish, trite, tiresome things that I should have told a son of mine.  I am so old that you will not take offense—­you will not mind listening to me, or forgetting the dull, prosy things I say about the curse of idleness, and the habits of cynical thinking, and the perils of vacant-minded indulgence.  You will forgive me—­and you will forget me.  That will be as it should be.  Good-by.”