Norman and I were left with the car. Poirot and one of the detectives went up to the door and rang. A neat parlor maid opened it. The detective spoke.

"I am a police officer, and I have a warrant to search this house." The girl gave a little scream, and a tall, handsome woman of middle age appeared behind her in the hall.

"Shut the door, Edith. They are burglars, I expect."

But Poirot swiftly inserted his foot in the door, and at the same moment blew a whistle. Instantly the other detectives ran up, and poured into the house, shutting the door behind them. Norman and I spent about five minutes cursing our forced inactivity. Finally the door reopened, and the men emerged, escorting three prisoners - a woman and two men. The woman, and one of the men, were taken to the second car. The other man was placed in our car by Poirot himself.

"I must go with the others, my friend. But have great care of this gentleman. You do not know him, no? Eh bien, let me present to you, Monsieur O'Murphy!"

O'Murphy! I gaped at him open-mouthed as we started again. He was not handcuffed, but I did not fancy he would try to escape. He sat there staring in front of him as though dazed. Anyway, Norman and I would be more than a match for him.

To my surprise, we still kept a northerly route. We were not returning to London, then! I was much puzzled. Suddenly, as the car slowed down, I recognized that we were close to Hendon Aerodrome. Immediately I grasped Poirot's idea. He proposed to reach France by aeroplane. It was a sporting idea, but, on the face of it, impracticable. A telegram would be far quicker. Time was everything. He must leave the personal glory of rescuing the Prime Minister to others. As we drew up, Major Norman jumped out, and a plain-clothes man took his place. He conferred with Poirot for a few minutes, and then went off briskly. I, too, jumped out, and caught Poirot by the arm.

"I congratulate you, old fellow! They have told you the hiding-place? But, look here, you must wire to France at once. You'll be too late if you go yourself."

Poirot looked at me curiously for a minute or two.

"Unfortunately, my friend, there are some things that cannot be sent by telegram."

At that moment Major Norman returned, accompanied by a young officer in the uniform of the Flying Corps.

"This is Captain Lyall, who will fly you over to France. He can start at once."

"Wrap up warmly, sir," said the young pilot. "I can lend you a coat, if you like." Poirot was consulting his enormous watch. He murmured to himself: "Yes, there is time - just time." Then he looked up, and bowed politely to the young officer. "I thank you, monsieur. But it is not I who am your passenger. It is this gentleman here."