"I cannot go as I am," declared Cervera, pa.s.sionately stamping her foot. "I am in evening dress--attired to receive a caller. I shall take cold if I go out of doors in--"

"Oh, you may change your dress," Nick curtly interrupted, the need of which was decidedly obvious. "I'll give you time for that."

"How very kind," sneered Cervera, with a bitter flash of her black eyes.

"You shall yet suffer for this affront, Detective Carter."

"All right," said Nick. "But I have no time to speculate upon it now, so get yourself ready. Wait a bit, my lady! I'll go along with you!"

"With me? You insult me!"

"Oh, no, I don't. I want a look at your chamber before letting you out of my sight. I've seen rooms with more than one way out, and I don't intend that you shall elude me."

"You're a suspicious coward, sir!"

"Stow all that, senora, and lead the way," commanded Nick, bluntly.

Pale and resentful, with a sneer on her lips, Cervera led the way through, the hall, playing her part so artfully that Nick, ignorant of her late interview with Rufus Venner, was not much inclined to suspect her of duplicity just then.

Upon reaching the top of the hall stairs, Cervera switched on another light, and then that which illumined her chamber, into which she haughtily led the detective.

"A fine affront to suffer," she bitterly exclaimed, throwing herself into a chair. "Your conduct is despicable! You are no gentleman!"

"I am a detective," retorted Nick, "and I come pretty near knowing my business."

"Oh! you do," sneered Cervera. "Plainly that is the limit of your knowledge. You may not be as wise as you think."

Nick made no reply, but looked sharply about the room.

It was a large, square chamber, and elaborately furnished. The two windows were well above the street, and offered no chance for escape.

There were but two doors, that leading into the hall and the one leading into a large closet in the opposite wall.

Nick opened the latter, and found the closet hung with Cervera's extensive wardrobe. He thrust his arm along the garments hanging at either side, and sounded the three walls, and then the closet floor, all of which appeared perfectly firm and solid.

Even these precautions seemed quite needless to Nick, however, it being a rented house, and Cervera presumably uninformed of his coming.

"Now, senora, you may have just ten minutes to make ready," said he, as he rejoined her. "I shall leave this chamber door open, and will wait for you in the adjoining hall. Can you whistle?"

"Whistle?"

"Yes, whistle! You know what it is to whistle, don't you?"

The sneer on Cervera's red lips, as she arose from her chair, became almost a smile.

"Yes, I can whistle after a fashion," she admitted.

"Well, then, you keep whistling all the time you are alone here," Nick sternly commanded. "I will let you out of my sight to make these changes, but not out of my hearing."

"Suspicious fool!"

"Fool or not, you keep whistling," said Nick, bluntly. "If you let up for so long as a second, I'll come over yonder threshold in a way that you'll not fancy."

"But suppose I want to brush my teeth?" inquired Cervera, with a vixenish light in her evil eyes. "I cannot whistle and brush my teeth, Detective Carter."

"You'll have plenty of time to brush your teeth at the Tombs," said Nick, sharply. "Now look lively, mark you, and--keep whistling."

Cervera at once began to whistle.

Nick removed the key from the chamber door, and sauntered out into the hall, where he kept his ears constantly alert.

Not for a moment did the whistling cease, nor was there the slightest change in tone or character.

Nick could not have taken a more effective method to serve his present purpose.

At the end of eight minutes the whistling ceased, and Cervera coldly cried:

"Now you may come in, Detective Carter. I am about ready to go with you."

Nick at once entered the chamber.

Cervera had changed her evening dress for a complete suit of black, and was standing in the middle of the room.

"I suppose," said she, staring icily at the detective, "that I ought to thank you for your consideration."

"Don't trouble yourself," said Nick, curtly. "I have no time to waste."

"Yet just one word, Detective Carter, before we go."

"Let it be brief, then."

"You are said to be a very clever man, and no doubt you think you have me dead to rights in this case," said Cervera, with a mocking curl of her thin lips.

"Decidedly so."

"Yet you will find, Detective Carter, that a clever woman can always fool and foil a clever man."

"But you, my lady, are very far from being a clever woman," retorted Nick, with a gesture of impatience, signifying that he wished to leave with her at once.

"Nevertheless, I shall beat you at the finish, make no mistake about that," cried Cervera, scornfully. "Now, sir, I will put on my wrap, and go with you where you please."

With the last remark, she approached a peg in the open closet, as if to take down a dark shawl.

Instead, she suddenly turned quickly around and cried, with a taunting laugh:

"So long, Detective Carter! I really feel quite sorry to bid you--good-by!"

Nick started like a man electrified.

Cervera merely had pressed the peg on which the shawl hung, whereupon the whole back of the closet seemed to fall away instantly, disclosing a lighted pa.s.sage beyond.