And, worse than all, I had still no certainty.  I could only surmise that the lady was the one I was in search of, for I had not as yet clapt eyes on her, and I had been to some extent driven to show my hand before I had made my ground good.  So the first thing I did on regaining my own compartment was to ring for Jules, the conductor, and put before him the photograph with which I was provided, and ask him if he recognized it.

“But perfectly.  It is the lady yonder,” he said promptly.  “Is it your own, or did you find it or annex it from next door?  Ah, your own; and what have you to do with her?”

“I may tell you some day, Jules.  For the present you must know that I am after her; I have to watch her, stick to her like her shadow until it is time to act.”

“An adventuress, eh?”

“She is in possession of what does not belong to her; something she abstracted from—­from—­Never mind where, and it must be recovered from her here, or after she leaves the car.”

“Afterwards, please.  We can’t have any scandal on board here.”

“Five hundred francs wouldn’t tempt you to let me have a free hand for just half an hour?  I could do it, say somewhere short of Basle, and on reaching there make off.  No one should be any the wiser, and they, the women, wouldn’t dare to make a fuss.”

“It’s I who do not dare—­not for twice five hundred francs.  My place is worth more than that; and if it is a dog’s life, it is better than lying on the straw.  Besides, there’s her friend the Colonel, he’ll be on the alert, you may depend.”

“So must I be, and I must find some way to circumvent him.  I’ll be even with him.  He sha’n’t beat me, the overbearing, hectoring brute.  It’s between him and me, and I think I’m a match for him.”

I spoke this confidently to my friend, who engaged for his part to do all in his power to assist, or at least to do nothing against me, and I was content to bide my time.  Pride goes before a fall.  I was not as clever as I thought, and shall have to tell you how seriously I had underrated his worth in the coming trial of strength.

As the train sped on and the night began to close in on us, I remained quietly in my berth, pondering over my position, and in considering the course I should adopt under various contingencies.  The first and most serious danger was that the lady should succeed in leaving the train at any of the intermediate stations at Basle, and so give me the slip.  There were Laon, Rheims, Chaumont, and the rest.

It must be my business to keep close watch against any evasion of this kind, and Jules had promised to help.  I did not look for any such attempt until far into the night, when the stations were empty and half-dark, and I agreed with Jules to divide the hours till daylight, he taking the first, I the last.  We were due at Basle at 5 A.M., and I expected to join forces then with Tiler, my colleague, coming from the side of Ostend, via Brussels and Strasburg.