“The letter,” he replied, “is with the expert of the State Department for translation.”

“What language is it in?” she demanded.

“Cipher language—­and a particularly difficult cipher it is.  Can you help us out, Mrs. Clephane?”

“I can’t, Mr. Harleston; I don’t know anything about ciphers.  And I told you the whole truth when I said that I neither knew what the envelope contained nor its purpose.  What disturbs me is how to explain to the French Ambassador the loss of the letter.”

“Tell him the exact truth,” said Harleston.  “It would have been better possibly had you told him this morning.”

“I thought you would return the letter to me,” she replied.

“I likely should, had I seen you before I turned it over to the State Department.  Now that it has passed out of my hands, it is a matter for the Secretary to decide.”

“But he will be advised by you!” she exclaimed.

“Advised, yes,—­dominated, no.  The only chance of the letter being returned to you, is that it does not affect this government.”

“Diplomacy then is willing to stoop to any crime or to profit by any wrong?” she mocked.

“I am afraid I must admit the accusation.  Everything is fair in love and war, you know—­and diplomacy is only a species of war.”

“Have I no redress for the outrage upon me, nor for the loss of the letter by reason of that outrage?”

“I’m afraid you’ll find the wheels of justice very slow-moving—­when they have to do with affairs diplomatic.”

“But the letter, sir?”

“You must remember, Mrs. Clephane, that I found the letter in an abandoned cab.”

“And now that you know to whom it belongs,” she flashed, “you will not return it?”

“Because I can’t!  Which brings us back to where we started—­and to dinner.”

“I will not dine with you!”

“Then let me dine with you!”

“No!”

“Fix it any way you wish, only so that we dine together,” he persisted.  “I’ve the cosiest little table reserved for us, and—­”

“Mr. Harleston,” the page was calling.  “Mr. Harles—­”

Harleston turned, and the boy saw him.

“Telephone, sir,” said he, giving Harleston the call slip.

“Will you excuse me a moment, Mrs. Clephane?” Harleston asked, and hurried out—­conscious all the while that Madeline Spencer and her companion were watching him.

“This is Police Headquarters, Mr. Harleston,” came the voice over the wire.  “Major Ranleigh wants to know if you will meet him at his office at ten o’clock tonight.  The Major was called out suddenly or he would have telephoned you, himself!”

“I’ll be on hand,” Harleston replied, hung up the receiver, and hurried back.

As he entered the red-room, he shot a covert glance toward the place where Mrs. Spencer and her companion had been sitting.

They were gone!