It was, indeed, a daring piece of work on the part of Karl von Eckenhardt.
After his encounter with Terence on the cliffs at Yarmouth he had succeeded in eluding the patrols and had taken refuge in London. Here he lay low as a Russian subject. A fortnight later, by means of a forged passport, he embarked at Shields upon a Swedish vessel bound for Gottenberg. Thence he returned to his native country, where during a period of activity at the German Admiralty he grew a full beard. He was far too wily to adopt false hair as a disguise, although he did not hesitate to dye his beard a ruddy tint.
Without difficulty, this time making use of an American passport and registering as a citizen of New York, he returned to England by a different route. After a short stay in Liverpool he went on to Glasgow, whence he transmitted valuable information to Berlin as a result of a casual acquaintanceship with an overseer of one of the Clyde shipyards.
Gaining increased confidence his next move was to install himself in the neighbourhood of Rosyth, in order to keep a watchful eye upon the movements of the Grand Fleet. Plentifully supplied with money, he assumed the honoured name of McNab, and completely deceiving a firm of house agents, succeeded in getting the tenancy of Tuilabrail.
Then, having engaged servants who with few exceptions were German secret agents domiciled long enough in Great Britain to disarm any suspicion of their nationality, he proceeded to get in touch with certain of the junior officers of the Fleet and some of the civil officials of the new and important dockyard of Rosyth.
Fortune seemed to smile on his efforts. Acting as a friend in need to a naval officer whose car had met with a breakdown, he found the beginning of a chain of acquaintances. His hospitality became a by-word amongst certain parties of naval men. He never asked questions upon Service matters. He relied upon his sharp ears and those of his minions to pick up useful information from the casual conversations of his guests. Young officers were at times, he reasoned, apt to forget the necessity for "official reticence and reserve."
One of his duties was to send a report to Berlin of all changes in the personnel of officers of the Fleet. This was a comparatively easy matter, since most appointments were published in the Press.
Another was to notify movements of individual ships, both naval and mercantile. This he did by means of a simple re-arrangement of the International Code, the news being sent by a comparatively low-powered wireless apparatus to a disguised trawler that was cruising regularly off the tail of the Dogger.
Unfortunately for him, Sub-Lieutenant Aubyn's appointment to the "Livingstone" did not appear in the papers; had it done so he would have been put upon his guard. Cool and calculating as he generally was, the suddenness with which he found himself confronted by Terence momentarily took him off his guard. In spite of his disguise the sub. recognized von Eckenhardt immediately.
It was an hour or more before Lieutenant Nixon returned, accompanied by a party of Marine Light Infantry and a number of Metropolitan police, who, amongst other duties, are entrusted with the guarding of his Majesty's Naval and Military establishments.