nd followed the clerk to the
box-office.

He was not yet out of sight when Lupin sprang from his box, worked the
lock of the next door and sat down beside the lady.

She gave a stifled cry.

"Hush!" he said. "I have to speak to you. It is most important."

"Ah!" she said, between her teeth. "Arsene Lupin!" He was dumbfounded.
For a moment he sat quiet, open-mouthed. The woman knew him! And not
only did she know him, but she had recognized him through his disguise!
Accustomed though he was to the most extraordinary and unusual events,
this disconcerted him.

He did not even dream of protesting and stammered:

"So you know?... So you know?..."

He snatched at the lady's veil and pulled it aside before she had time
to defend herself:

"What!" he muttered, with increased amazement. "Is it possible?"

It was the woman whom he had seen at Daubrecq's a few days earlier, the
woman who had raised her dagger against Daubrecq and who had intended to
stab him with all the strength of her hatred.

It was her turn to be taken aback:

"What! Have you seen me before?..."

"Yes, the other night, at his house... I saw what you tried to do..."

She made a movement to escape. He held her back and, speaking with great
eagerness:

"I must know who you are," he said. "That was why I had Daubrecq
telephoned for."

She looked aghast:

"Do you mean to say it was not the Marquis d'Albufex?"

"No, it was one of my assistants."

"Then Daubrecq will come back?..."

"Yes, but we have time... Listen to me... We must meet again... He is
your enemy... I will save you from him..."

"Why should you? What is your object?"

"Do not distrust me... it is quite certain that our interests are
identical... Where can I see you? To-morrow, surely? At what time? And
where?"

"Well..."

She looked at him with obvious hesitation, not knowing what to do, on
the point of speaking and yet full of uneasiness and doubt.

He pressed her:

"Oh, I entreat you... answer me just one word... and at once... It would
be a pity for him to find me here... I entreat you..."

She answered sharply:

"My name doesn't matter... We will see each other first and you shall
explain to me... Yes, we will meet... Listen, to-morrow, at three
o'clock, at the corner of the Boulevard..."

At that exact moment, the door of the box opened, so to speak, with a
bang, and Daubrecq appeared.

"Rats!" Lupin mumbled, under his breath, furious at being caught before