She gave a slight start and began to follow him.

When he discovered this and turned around, asking why she was dogging his footsteps, she gave the above recorded answer.

By her mentioning his name, he realized that she knew him, and he at once suspected she was La Croix’s wife.

He resolved to fathom the mystery of her identity.

Seizing her arm, he exclaimed: 

“Hold on a moment.”

“Well?” she asked, pausing obediently.

“I want to know who you are that takes such a deep interest in my welfare.  I want to know who it is that knows me—­who knows all about the private business which has brought me to this city.  Speak out.  Who are you?”

“Your friend,” replied the mysterious unknown.

“What is your name?” he persisted.

“I must decline to tell you.”

“But I won’t take a refusal.  You must speak.”

“No.  Allow me to retain my incognito.  It were best for us both.”

Old King Brady was determined to know her, however, and he seized her long crepe veil and attempted to remove it from her face.

A subdued cry of anger escaped her.

“Let that be!” she exclaimed, imperiously.

“Madam, I must see who you are!” he persisted.

“Is this the gratitude you show for the favor I have done you?”

“You have aroused my curiosity.”

“Stand back, sir.  Don’t you dare lay a hand on me again.”

“Why,” he laughed, “is it dangerous?”

“Very!”

“How?”

She drew a slender dagger from the folds of her dark dress, and as the lamplight glanced upon the blade, it flashed as she drew it back.

Old King Brady was startled.

He did not expect to see anything like this.

Raising the dagger, the mysterious woman hissed: 

“If you attempt to penetrate my identity, I shall stab you!”

There was a ring of intense earnestness to her voice, and it froze the smile that rose to the old detective’s face.

He regarded her with a puzzled look.

It now began to dawn upon his mind that she was not Mrs. La Croix after all.  The voice was different.  She was shorter and stouter than the smuggler’s wife.  Her actions were different.

To gain time to form a different tactic he exclaimed: 

“How can you be a friend of mine if you are going to stab me?”

“I am bound to keep my identity a secret,” she replied, firmly.

“What object have you in befriending me?”

“You are a brave man and a dutiful officer.  I know you are only following up this case because you were ordered to do so.  I therefore don’t wish to see you perish.”

“How do you know I’m doomed to get killed?”

“Because I heard your enemies plot your destruction.”

“In that case they know we are here on their trail?”