“Phrony, you must go home,” said Keith.

For a second a spasm shot over her face; then a ray of light seemed to flit across it, and then it died out.

She shook her head.

“No, I’ll never go back there,” she said.

“Oh, yes, you will—­you must.  I will take you back.  The mountain air will restore you, and—­” She was shaking her head, but the look in her eyes showed that she was thinking of something far off.

“No—­no!”

“I will take you,” repeated Keith.  “Your grandfather will be—­he will be all right.  He has just been here hunting for you.”

The expression on her face was so singular that Keith put his hand on her arm.  To his horror, she burst into a laugh.  It was so unreal that men passing glanced at her quickly, and, as they passed on, turned and looked back again.

“Well, good-by; I must find my husband,” she said, holding out her hand nervously and speaking in a hurried manner.  “He’s got the baby with him.  Tell ’em at home I’m right well, and the baby is exactly like grandmother, but prettier, of course.”  She laughed again as she turned away and started off hastily.

Keith caught up with her.

“But, Phrony—­” But she hurried on, shaking her head, and talking to herself about finding her baby and about its beauty.  Keith kept up with her, put his hand in his pocket, and taking out several bills, handed them to her.

“Here, you must take this, and tell me where you are staying.”

She took the money mechanically.

“Where am I?  Oh!—­where am I staying?  Sixteen Himmelstrasse, third floor—­yes, that’s it.  No:—­18 Rue Petits Champs, troisieme etage.  Oh, no:—­241 Hill Street.  I’ll show you the baby.  I must get it now.”  And she sped away, coughing.

Keith, having watched her till she disappeared, walked on in deep reflection, hardly knowing what course to take.  Presently his brow cleared.  He turned and went rapidly back to the great office building where Wickersham had his offices on the first floor.  He asked for Mr. Wickersham.  A clerk came forward.  Mr. Wickersham was not in town.  No, he did not know when he would be back.

After a few more questions as to the possible time of his return, Keith left his card.

That evening Keith went to the address that Phrony had given him.  It was a small lodging-house of, perhaps, the tenth rate.  The dowdy woman in charge remembered a young woman such as he described.  She was ill and rather crazy and had left several weeks before.  She had no idea where she had gone.  She did not know her name.  Sometimes she called herself “Miss Tripper,” sometimes “Mrs. Wickersham.”

Keith took a cab and drove to the detective agency where Dave Dennison had his office.  Keith told him why he had come, and Dave listened with tightened lips and eyes in which the flame burned deeper and deeper.

“I’ll find her,” he said.