"Quite impossible, I should say. There were guards at the entrance to the room itself, and sentries were posted at the great doors below. In fact, I would be prepared to swear that no one entered the room save myself and my brother's faithful friend."
"Your brother's friend?" von Marquart repeated suspiciously. "Who is he? Perhaps he can throw some light upon the affair."
This point had never struck me, and I thereupon told Strekwitz to summon Bertram to my presence without delay. He did so, and a few minutes later, the man we wanted entered the room. Strekwitz had told him nothing, so that he was quite unprepared for the news I had to give him. On hearing it his grief was as great, and plainly as sincere, as my own had been.
"I can scarcely believe it," he said, after he had heard what we had to tell. "What possible motive can anyone have had for such a dastardly deed?"
I could furnish him with no answer that would be in any way satisfactory. Strekwitz inclined to the belief that it was the work of the enemy—an act of revenge, in fact, for the defeat they had suffered at our hands. Von Marquart, however, ridiculed the notion.
"No," he said, "there is more behind it than meets the eye. We must look elsewhere for a solution of the mystery."
Suddenly Bertram uttered an exclamation.
"Why on earth didn't I think of it sooner?" he cried. "If I'm not mistaken, I can explain everything."
"What do you mean?" I asked impatiently. "What do you remember? Tell us quickly."
"The man I ran into, in the street at Zaarfburg," he replied. "Rodriguez, who was with us in South America. Was it possible that his appearance in the city was only a coincidence, or had he some more sinister object in view? He was aware of the mysterious marks upon your brother's body, and knew they were connected with the hidden diamonds. Seeing that he was dead, and that he might never have another opportunity, is it not quite possible that he would be anxious to penetrate the secret before it was too late?"