It was about ten in the morning when Bouchardon confronted Zelle with the text of the first two telagrams. Recalling the day, he would note, "Since I had to play a careful game, I closed my door to everyone, spreading the news that I had gone to a prison in Fresnes for some hearing. Thus while the press was looking for me elsewhere, I prepared myself to meet Mata Hari with the convicting evidence of the Third War Council."

It was a warm day, a premature taste of June in the depths of March. Bouchardon's office was dark: the blinds lowered, the lamp light trained on the prisoner's chair. On entering the room she also noticed that his desk had been cleared of everything except a plain brown folder.

Bouchardon began on a seemingly minor point: "You mentioned in a previous session that you were not able to tell the German military attache von Kalle anything because you knew nothing of importance. Is that correct?"

She nodded. "I don't recall specifically having said that, captain, but it is correct."

"And is it also correct that you approached von Kalle under the pretense of clearing up a misunderstanding that led to your detention in London?"

"Yes."

Bouchardon then laid a sheet of blank stationery and a pencil on the desk in front of her. He had still not touched the folder.

"Let me offer you some advice, madame. A full confession at this point would save us both a great deal of time and trouble."

"I'm afraid I don't know what you're talking about, captain."

Then, finally—and rather melodramatically—opening that brown folder: "I am talking about material evidence of your guilt, madame. I'm talking about this."

There were three typewritten pages in the folder, but Bouchardon removed only one. He would later refer to this page as his "trump card," then still later as the "death warrant." He would also note that he had deliberately memorized the text in order to watch the small changes in her facial expression as he spoke.

"December thirteenth, von Kalle to Spangler. 'Agent H-21 of Central Information has arrived here requesting funds and instructions. She has feigned to accept services of French Espionage Bureau and to carry out trial mission on their account. She intended to travel from Spain to Holland aboard the Hollandia, but was arrested in Falmouth when mistaken for another. Once error was recognized, she returned to Spain because of continued British mistrust. Now requests advice and operational assistance.’"

She remained still, betraying not the slightest emotion. “I believe that there has been an error, captain. Yes, there must have been an error.”

“I hardly think so, madame.”

“Then a joke. Someone is playing a dreadful joke.”

“No joke either.”

“Then someone is lying. Yes, someone is maliciously lying.”

"No, madame. You are the only one who is lying. Yes, you."

Next Bouchardon proceeded to read the text of the second cable:

"December fourteenth, 1916. Spangler's response to von Kalle.