"That was the fellow right enough," he soliloquised. "Had I been informed directly the Air people made the discovery, I'd have nabbed him before this."
It was a few days after Karl von Preussen's hasty and almost panic-stricken exodus from Edinburgh. Entwistle, Secret Service agent, with a highly respectable record, had been called in by the authorities to trace the elusive spy. As usual, he was not consulted until after the police had declared themselves baffled. No doubt it was a tribute to Entwistle's sagacity, but he looked upon it in a totally different light. To him it meant precious hours and minutes wasted.
He remembered the wanted man. Entwistle was one of those comparatively rare individuals who hardly ever forget a face. Disguised as a country parson, he was returning from a case at Aberdeen—he had convinced the naval authorities the whole thing was a mare's nest and that a supposed spy was a harmless professor of a Scottish University—when, having to change at Nedderburn Junction, he found himself in the same compartment with the man whom the Admiralty, War Office, and Air Ministry wanted most particularly.
And when von Preussen showed his railway warrant to the ticket inspector, Entwistle, taking cover behind the Church Times, had memorised the particulars written on the buff form. It was not idle curiosity. It was to him a mental exercise. During the brief instant in which the inspector was holding the warrant to the light of the carriage lamp Entwistle had committed the following facts to memory: the number and date of the warrant, the holder's name and rank, his points of departure and his destination—details that were jotted down at the first opportunity in the Secret Service agent's pocket-book.
Entwistle was sitting in his study at his house in Barborough. The windows were wide open. It was a bright, sunny morning, and from where he sat he could see the rugged outlines of the distant hills and the tall chimneys of the factories in the valleys.
As he sat scanning the newly-arrived dossier of his latest case, Entwistle's thoughts went back to other scenes. The hills above Blackberry Cross and towards Tarleigh reminded him of the von Eitelwurmer case.
"Wonder if this Fennelburt fellow (of course, that's an assumed name) has anything to do with the late Herr Eitelwurmer?" he mused. "May as well go through those papers again, and perhaps it would be advisable to look up the von Gobendorff case."
He unlocked a drawer and pulled out two bulky packets of documents, neatly tied with string. Entwistle had a distaste for red tape, both metaphorically and literally. For the best part of an hour he busied himself with the various and for the most part faulty clues, endeavouring from the tangled skein to weave a thread of conclusive facts.
The offer of the one hundred pounds reward had had its disadvantages. Amateur detectives and others attracted by the offer had seen "Captain Fennelburt" in a dozen or more different places at approximately the same time. Copies of letters from these individuals had been included in the dossier sent to Entwistle from Scotland Yard. One was from a farmer at Penzance, who was certain that he saw the wanted man making for Poldene Air Station. Another emanated from a fisherman at Wick, who stated that an R.A.F. officer answering to the description of Captain Fennelburt stopped him and inquired the way to Loch Thrumster Flying School. Yet another correspondent, hailing from Ramsgate, reported that the spy was boarding at a small house near Pegwell Bay.
"Even in these days of high speed in aviation," thought Entwistle, "there are limits. We have yet to find conclusive evidence of a man starting from Wick, say, at 9 A.M. and finishing at Penzance at 11 A.M.—650 miles in two hours. And when he stops on the way to partake of refreshments at Ramsgate—involving a detour of another couple of hundred miles—the imagination is stretched beyond breaking-point. I'm afraid these worthy people are following the red-herring trail. The R.A.F. uniform has put them on a false scent. Now, if I were in Captain Fennelburt's position—without, presumably, a change of clothes—in a fairly distinctive uniform, what would I do?"