"Now, how did that precious treasure get here?" he asked himself. "Lord Rayburn would as soon have cut off his own hand as given away one of those beloved children of his."
He forced the catch on the conservatory door and hastened into the laboratory. A moment later he was bending over the dead body of his chief with that calm, self-centred feeling that comes to most of us in the presence of sudden and unexpected death. There were certain things to be done, and Hayter went about them quite methodically. Then his eye caught sight of the open drawer with the key still in it, and with a strange suspicion in his mind he searched in the little cotton-wool nest for the big diamond which ought to have been there.
Five minutes later he had aroused the household and was holding Scotland Yard at the other end of the telephone, and barely half an hour afterwards he was telling his story to an inspector of police.
"Let me have that again, Mr. Hayter," Inspector Jones said. "I want to be quite clear. Señor Viantes came down here, at his own suggestion, to meet a man who has been his greatest enemy for the last twenty years."
"You have seen the letter," Hayter said curtly.
"Oh, yes. Now, what sort of a man is this Spanish scientist? As mad as most of them, I suppose?"
"Madmen don't steal historic diamonds," Hajter said. "I don't want to teach you your business, Inspector, but that man stole the diamond, and probably at the same time dropped the spray of orchid which I have in my buttonhole, and which I picked up, as I told you, outside the conservatory door when I was forcing it. To my mind, the thing is quite plain. Lord Kayburn has been murdered, and the murderer escaped in his car, which he brought down here alone for the purpose of getting away quickly. Now, it seems to me that it is up to you to go back to London and interview Señor Viantes without the slightest delay. That is my opinion."
"Perhaps you are right," the Inspector conceded. "And as you saw the Spaniard, you had better come along."
It was quite late in the evening before Hayter and Inspector Jones found themselves in Bloomsbury, face to face with the Spanish scientist in the latter's sitting-room. But directly Hayter entered the room his face fell.
"There is some mistake here, I am afraid," he murmured. "If this is Señor Viantes, then I have never seen him before. It was not he who called upon Lord Rayburn."