At his hotel, when he reached there, Mr. Grimm found Miss Thorne’s card—­and he drew a long breath; at his office he found another of her cards, and he drew another long breath.  He did like corroborative details, did Mr. Grimm, and, of course, this—!  On the following day Miss Thorne accompanied him to Alexandria, and they were driven in a closed carriage out toward the western edge of the city.  Finally the carriage stopped at a signal from Mr. Grimm, and he assisted Miss Thorne out, after which he turned and spoke to some one remaining inside—­a man.

“The house is two blocks west, along that street there,” he explained, and he indicated an intersecting thoroughfare just ahead.  “It is number ninety-seven.  Five minutes after we enter you will drive up in front of the door and wait.  If we don’t return in fifteen minutes—­come in after us!”

“Do you anticipate danger?” Miss Thorne queried quickly.

“If I had anticipated danger,” replied Mr. Grimm, “I should not have permitted you to come with me.”

They entered the house—­number ninety-seven—­with a key which Mr. Grimm produced, and a minute or so later walked into a room where three men were sitting.  One of them was of a coarse, repulsive type, large and heavy; another rather dapper, of superficial polish, evidently a foreigner, and the third—­the third was Ambassador Boissegur!

“Good morning, gentlemen!” Mr. Grimm greeted them, then ceremoniously:  “Monsieur Boissegur, your carriage is at the door.”

The three men came to their feet instantly, and one of them—­he of the heavy face—­drew a revolver.  Mr. Grimm faced him placidly.

“Do you know what would happen to you if you killed me?” he inquired pleasantly.  “You wouldn’t live three minutes.  Do you imagine I came in here blindly?  There are a dozen men guarding the entrances to the house—­a pistol shot would bring them in.  Put down the gun!”

Eyes challenged eyes for one long tense instant, and the man carefully laid the weapon on the table.  Mr. Grimm strolled over and picked it up, after which he glanced inquiringly at the other man—­the ambassador’s second guard.

“And you are the gentleman, I dare say, who made the necessary trips to the ambassador’s house, probably using his latch-key?” he remarked interrogatively.  “First for the letters to be signed, and again for the cigarettes?”

There was no answer and Mr. Grimm turned questioningly to Monsieur Boissegur, silent, white of face, motionless.

“Yes, Monsieur,” the ambassador burst out suddenly.  His eyes were fixed unwaveringly on Miss Thorne.

“And your escape, Monsieur?” continued Mr. Grimm.

“I did escape, Monsieur, last night,” the ambassador explained, “but they knew it immediately—­they pursued me into my own house, these two and another—­and dragged me back here! Mon Dieu, Monsieur, c’est—!”

“That’s all that’s necessary,” remarked Mr. Grimm.  “You are free to go now.”