spy, had voyaged from America to England not for the purposes of trade but to get hold of that mutilated document now reposing in my pocket. Why he had only got half the letter and what had happened to the other half was more than I could say ... it sufficed for me to know that its importance to somebody was sufficient to warrant a journey on its behalf from one side to the other of the Atlantic.

As I opened the bag my fingers encountered a hard substance, as of metal, embedded in the slack of the lining in the joints of the mouth. At first I thought it was a coin, then I felt some kind of clasp or fastening behind it and it seemed to be a brooch. Out came my pocket knife again and there lay a small silver star, about as big as a regimental cap badge, embedded in the thin canvas. It bore an inscription. In stencilled letters I read:

O2 G
Abt. VII.

Here was Dr. Semlin's real visiting-card.

I held in my hand a badge of the German secret police.

You cannot penetrate far behind the scenes in Germany without coming across the traces of Section Seven of the Berlin Police Presidency, the section that is known euphemistically as that of the Political Police. Ostensibly it attends to the safety of the monarch, and of distinguished personages generally, and the numerous suite that used to accompany the Kaiser on his visits to England invariably included two or three top-hatted representatives of the section.

The ramifications of Abteilung Sieben are, in reality, much wider. It does such work in connection with the newspapers as is even too dirty for the German Foreign Office to touch, comprising everything from the launching of personal attacks in obscure blackmailing sheets against inconvenient politicians to the escorting of unpleasantly truthful foreign correspondents to the frontier. It is the obedient handmaiden of the Intelligence Department of both War Office and Admiralty in Germany, and renders faithful service to the espionage which is constantly maintained on officials, politicians, the clergy and the general public in that land of careful organisation.

Section Seven is a vast subterranean department. Always working in the dark, its political complexion is a handy cloak for blacker and more sinister activities. It is frequently entrusted with commissions of which it would be inexpedient for official Germany to have cognizance and of which, accordingly, official Germany can always safely repudiate when occasion demands.

I thrust the pin of the badge into my braces and fastened it there, crammed the rest of the dead man's effects into his bag, stuck his hat upon my head and threw his overcoat on my arm, picked up his bag and crept away. In another minute I was back in my room, my brain aflame with the fire of a great enterprise.

Here, to my hand, lay the key of that locked land which held the secret of my lost brother. The question I had been asking myself, ever since I had first discovered the dead man's American papers of identity, was this. Had I the nerve to avail myself of Semlin's American passport to get into Germany? The answer to that question lay in the little silver badge. I knew that no German official, whatever his standing, whatever his orders, would refuse passage to the silver star of Section Seven. It need only be used, too, as a last resource, for I had my papers as a neutral. Could I but once set foot in Germany, I was quite ready to depend on my wits to see me through. One advantage, I knew, I must forgo. That was the half-letter in its canvas case.

If that document was of importance to Section Seven of the German Police, then it was of equal, nay, of greater importance to my country. If I went, that should remain behind in safe keeping. On that I was determined.

"Never before, since the war began," I told myself, "can any Englishman have had such an opportunity vouchsafed to him for getting easily and safely into that jealously guarded land as you have now! You have plenty of money, what with your own and this ..." and I fingered Semlin's wad of notes, "and provided you can keep your head sufficiently to remember always that you are a German, once over the frontier you should be able to give the Huns the slip and try and follow up the trail of poor Francis.

"And maybe," I argued further (so easily is one's better judgment defeated when one is young and set on a thing), "maybe in German surroundings, you may get some sense into that mysterious jingle you got from Dicky Allerton as the sole existing clue to the disappearance of Francis."

Nevertheless, I wavered. The risks were awful. I had to get out of that evil hotel in the guise of Dr. Semlin, with, as the sole safeguard against exposure, should I fall in with the dead man's employers or friends, that slight and possibly imaginative resemblance between him and me: I had to take such measures as would prevent the fraud from being detected when the body was discovered in the hotel: above all, I had to ascertain, before I could definitely resolve to push on into Germany, whether Semlin was already known to the people at the hotel or whether—as I surmised to be the case—this was also his first visit to the house in the Vos in't Tuintje.

In any case, I was quite determined in my own mind that the only way to get out of the place with Semlin's document without considerable unpleasantness, if not grave danger, would be to transfer his identity and effects to myself and vice versa. When I saw the way a little clearer I could decide whether to take the supreme risk and adventure myself into the enemy's country.

Whatever I was going to do, there were not many hours of the night left in which to act, and I was determined to be out of that house of ill omen before day dawned. If I could get clear of the hotel and at the same time ascertain that Semlin was as much a stranger there as myself, I could decide on my further course of action in the greater freedom of the streets of Rotterdam. One thing was certain: the waiter had let the question of Semlin's papers stand over until the morning, as he had done in my case, for Semlin still had his passport in his possession.

After all, if Semlin was unknown at the hotel, the waiter had only seen him for the same brief moment as he had seen me.

Thus I reasoned and argued with myself, but in the meantime I acted. I had nothing compromising in my suit-case, so that caused no difficulty. My British passport and permit and anything bearing any relation to my personality, such as my watch and cigarette case, both of which were engraved with my initials, I transferred to the dead man's pockets. As I bent over the stiff, cold figure with its livid face and clutching fingers, I felt a difficulty which I had hitherto resolutely shirked forcing itself squarely into the forefront of my mind.

What was I going to do about the body?

At that moment came a low knocking.

With a sudden sinking at the heart I remembered I had forgotten to lock the door.

CHAPTER V

THE LADY OF THE VOS IN'T TUINTJE

Here was Destiny knocking at the door. In that instant my mind was made up. For the moment, at any rate, I had every card in my hands. I would bluff these stodgy Huns: I would brazen it out: I would be Semlin and go through with it to the bitter end, aye, and if it took me to the very gates of Hell.

The knocking was repeated.

"May one come in?" said a woman's voice in German.

I stepped across the corpse and opened the door a foot or so.

There stood a woman with a lamp. She was a middle-aged woman with an egg-shaped face, fat and white and puffy, and pale, crafty eyes. She was in her outdoor clothes, with an enormous vulgar-looking hat and an old-fashioned sealskin cape with a high collar. The cape which was glistening with rain was half open, and displayed a vast bosom tightly compressed into a white silk blouse. In one hand she carried an oil lamp.

"Frau Schratt," she said by