“This evening,” the Baron went on, “I hope your two assistants will be here. This car will then be at your disposal to take you backwards and forwards from the castle.”

To protest against such a site was, apparently, useless. All that Geoffrey could do was to warn the Baron that the results were not likely to be too good.

“Well,” he laughed, “I’ve bought the plant, and if I choose to erect it anywhere, I suppose I am at liberty to do so. You, Mr. Falconer, with your expert knowledge, will, no doubt, be able to make it work all right!” he said good-humouredly.

“Well—I’ll try,” Geoffrey replied, and on his return to Zenta he sat down and wrote a long letter to Sylvia, telling her his whereabouts, and how the material had been addressed to Arad wrongly, of his life with the Baron, and of the rather unsatisfactory site that had been chosen.

He wrote four closely-filled pages, and having finished took it to one of the small rooms where Françoise was sitting reading a French novel.

“The post goes out every night at seven o’clock,” she said. “If you will put it in the rack by the front entrance Karl will see that it is put with the others this evening. Ludwig goes in the light car, and takes the letters into Deva. They go by road to Nagy-Károly to-morrow morning, and on by rail.”

Next day two shrewd-looking Austrian engineers presented themselves as Geoffrey’s assistants. Both spoke French, and when Falconer questioned them he discovered that the elder of the pair knew a good deal about radio-telephony.

They therefore set to work to open the huge boxes of apparatus which had been over three months on their way from Chelmsford. Each was marked, and they, of course, only unpacked one complete set, together with the aerial masts and wires. This work took three days, after which the whole of the plant was carried up by horses through the forest to the clearing which had been made near the top of the mountain.

Day by day Geoffrey was out there with his two assistants, first erecting the aerial—one of the newest type—and then making an “earth” by sinking three-foot copper plates edgewise in the form of a ring, and connecting all of them to a central point. Each evening he was back at the castle, where he spent many pleasant hours with the Baron and his charming niece. The latter, indeed, took him on several occasions to see the most delightful pieces of mountain scenery while the Baron, hearty and full of bonhomie, was keenly interested to watch Geoffrey at work fitting the complicated-looking apparatus.

Yet, curiously enough, Geoffrey’s strange feeling of apprehension had not passed. He could not rid himself of that creepy feeling which had stolen over him on the night of his arrival at the castle of Zenta. Why, he could not tell.