esk and tossed me a small revolver.

"Estere waits below in the carriage. He will drive with you to the
station. You take the ordinary express to Marcon. There an automobile
waits for you, and you must start for the convent. The driver has the
route. Remember this. You must go alone. You must overtake them. Use
force if necessary. If you fail--Isobel is lost!"

"I shall not fail!" I answered grimly.

"Bring her back, Arnold," he said, with a sudden change in his tone. "I
want to see her once more."

I left him there, and glancing upwards from the street as the carriage
drove off, I waved my hand to the slim black figure at the window, whose
wan, weary eyes watched our departure with an expression which at the
time I could not fathom. It was not until I was actually in the train
that I remembered what Lady Delahaye's silent departure might mean for
him.

CHAPTER V

Our plans were skilfully enough laid, but the Archduchess also had
missed nothing. We rushed through the village of Argueil without having
seen any sign of the carriage, and it was not until we had reached the
vineyard-bordered road beyond that we saw it at last climbing the last
hill to the convent.

"Shall we catch it?" I gasped.

The _chauffeur_ only smiled.

"Monsieur may rest assured," he answered, changing into his fourth
speed, notwithstanding the slight ascent.

Half-way up the hill we were barely one hundred yards behind. The man
glanced at me for instructions.

"Blow your horn," I said.

He obeyed. The carriage drew to the side of the road. We rushed by, and
I caught a glimpse of three faces. My spirits rose. There was only the
Baron to deal with. Madame Richard and Isobel were the other occupants
of the carriage.

"Stop, and draw the car across the road!" I ordered.

The man obeyed. I sprang to the ground. The Baron had his head out of
the window, and the driver was flogging his horses.

"If you do not stop," I called out, "I shall shoot your horses."

The driver took no notice. He had flogged his horses into a gallop, and
was coming straight at me. I fired, and one of the horses, after a wild
plunge came down, dragging the other with him, and breaking the pole.
The driver was thrown on to the top of them and rolled off into the
hedge, cursing volubly. The Baron leaned out of the window, and he had
something in his hand which gleamed like silver in the sunlight.

"I have had enough of you, my young friend," he said fier