The liquid melody of the music rose in a rippling flow, coming through the closed windows in soft minor chords. Standing there beside her, in the outer darkness and cold, Prescott began to understand the girl's feeling, the feeling of the hunted, who looks upon ease and joy. The house was gleaming with lights, even the measured tread of the dancers mingled with the flow of music; but here, outside, the wind began to whistle icily down the street, and the girl bent her head to its edge.

"You must go back at once to Miss Grayson's," urged Prescott, "and you must not come out again like this."

"You command merely for me to disobey," she said coolly. "By what right do you seek to direct my actions?"

"By the right of wisdom, or necessity, whichever you choose to call it,"

he replied. "Since you will not, of your own choice, care for yourself, I shall try to make you do so. Come!"

He put his hand upon her again. She sought to draw away, but he would not let go, and gradually she yielded.

"What a great thing is brute force! at least, you men think so," she said, as they walked slowly up the street.

"Yes, when properly exerted, as in the present instance."

They went on, the lights in the house became dimmer, and the sound of the music and the tread of the dance reached them no more.

She looked up into his face presently.

"Tell me one thing," she said.

"Certainly."

"Who is Helen?"

"Who is Helen?"

"Yes, I heard that man say how well she was looking to-night, and you agreed."

"We were both right. Helen is Miss Helen Harley, and they say she is the most beautiful woman in Richmond. She is the sister of Colonel Harley, one of our noted cavalry leaders."

She was silent for a little while, and then Prescott said:

"Now will you answer a question of mine?"

"I should like to hear the question first."

"Where were you hidden when we searched Miss Grayson's house?"

"That I will never tell you," she replied with sudden energy.

"Oh, well, don't do it then," he said in some disappointment.

They were now three or four squares away from the presidential mansion and were clothed in darkness, and silence save when the frozen snow crackled crisply under their feet.

"You cannot go any farther with me," she said. "I have warned you before that you must not risk yourself in my behalf."

"But if I choose to do so, nevertheless."

"Then I shall go back there to the house, where they are dancing."

She spoke in such a resolute tone that Prescott could not doubt her intent.

"If you promise to return at once to Miss Grayson's cottage I shall leave you here," he said.

"I make the promise, but for the present only," she replied. "You must remember that we are enemies; you are of the South, and I am treated as an enemy in Richmond. Good-night!"

She left him so quickly that he did not realize her departure until he saw her form flicker in the darkness and then disappear completely. A faint smile appeared on his face.

"No woman can ever successfully play the role of a man," he said to himself. Despite her former denial and her air of truth he was still thinking of her as a spy.

Then he walked thoughtfully back to the presidential mansion.

"You must have found that a most interesting cigar," said Talbot to him when he returned to the house.

"The most interesting one I ever smoked," replied Prescott.

Prescott found himself again with Mrs. Markham and walked with her into one of the smaller parlours, where Mr. Sefton, Winthrop, Raymond, Redfield and others were discussing a topic with an appearance of great earnestness.

"It is certainly a mystery, one of the most remarkable that I have ever encountered," said the Secretary with emphasis, as Prescott and Mrs.

Markham joined them. "We are sure that it was a woman, a woman in a brown cloak and brown dress, and that she is yet in Richmond, but we are sure of nothing else. So far as our efforts are concerned, she might as well be in St. Petersburg as here in the capital city of the South.

Perhaps the military can give us a suggestion. What do you think of it, Captain Prescott?"

He turned his keen, cold eye on Prescott, who never quivered.

"I, Mr. Sefton?" he replied. "I have no thoughts at all upon such a subject; for two reasons: first, my training as a soldier tells me to let alone affairs which are not my own; and second, you say this spy is a woman; know then that it is the prayer of every soldier that G.o.d will preserve him from any military duty which has to do with a woman, as it means sure defeat."

There was a laugh, and Mrs. Markham asked:

"Do you mean the second of your reasons as truth or as a mere compliment to my s.e.x?"

"Madam," replied Prescott with a bow, "you are a living ill.u.s.tration of the fact that I could mean the truth only."

"But to return to the question of the spy," said Mr. Sefton, tenaciously, "have you really no opinion, Captain Prescott? I have heard that you a.s.sisted Mr. Talbot when he was detailed to search Miss Grayson's house--a most commendable piece of zeal on your part--and I thought it showed your great interest in the matter."

"Captain Prescott," said Mrs. Markham, "I am surprised at you. You really helped in the searching of Miss Grayson's house! The idea of a soldier doing such work when he doesn't have to!"

Prescott laughed lightly--a cloak for his real feelings--as Mrs.

Markham's frank criticism stung him a little.

"It was pure chance, Mrs. Markham. I happened to be near there when Talbot pa.s.sed with his detail, and as he and I are the best of friends, I went with him wholly out of curiosity, I a.s.sure you--not the best of motives, I am willing to admit."

"Then I am to imply, Mrs. Markham," said the Secretary in his smooth voice, "that you condemn me for inst.i.tuting such a search. But the ladies, if you will pardon me for saying it, are the most zealous upholders of the war, and now I ask you how are we men to carry it on if we do not take warlike measures."

She shrugged her shoulders and the Secretary turned his attention again to Prescott.

"What do you think of our chances of capture, Captain?" he said. "Shall we take this woman?"

"I don't think so," replied Prescott, meeting the Secretary's eye squarely. "First, you have no clue beyond the appearance of a woman wearing a certain style of costume in the Government building on a certain day. You have made no progress whatever beyond that. Now, whoever this woman may be, she must be very clever, and I should think, too, that she has friends in the city who are helping her."