I promised, and as they drove off to the station I stood waving my hand to the departing visitors.
A week later I had word from Cuxhaven of the arrival of the Hohenzollern from Trondhjem, and at once returned to the Marmor Palace, where on the night of my arrival the Crown-Prince, wearing his Saxon Uhlan uniform, entered my room, gaily exclaiming:
"Well, Heltzendorff, how are things on the Lake of Garda, eh?"
I briefly explained where I had been, and then, as he lit a cigarette, standing astride near the fireplace, I asked permission to speak upon a confidential matter.
"More trouble, eh?" he asked, with a grin and a shrug of the shoulders.
"I do not know," I said seriously, and then, in brief, I related how the man Aranda had arrived with the girl Lola at the hotel, and what had followed.
As soon as I mentioned the Lungtevere Mellini, that rather aristocratic street, which runs parallel with the Tiber on the outskirts of Rome, His Highness started, his face blanched instantly, and he bit his thin lip.
"Himmel!" he gasped. "The fellow knows that I took the name of Nebelthau! Impossible!"
"But he does," I said quietly. "He is undoubtedly in possession of some secret concerning your visit to Rome last December."
In His Highness's eyes I noticed a keen, desperate expression which I had scarcely ever seen there before.