"Only since last night, sir," replied the butler, "but the circumstances are queer. He dined out with some City gentlemen, somewhere, last night, and he came home about ten o'clock. He wasn't in the house long. He went into his laboratory--he spends a lot of time in experimenting in chemistry, you know, sir--and he called me in there. 'I'm going out again for an hour, Grayson,' he says. 'I shall be in at eleven: don't go to bed, for I want to see you for a minute or two.' Of course, there was nothing in that, Mr. Purdie, and I waited for him. But he never came home--and no message came. He never came home at all--and this morning I've telephoned to his two clubs, and to one or two other places in the City--nobody's seen or heard anything of him. And I can't think what's happened--it's all so unlike his habits." "He didn't tell you where he was going?" asked Purdie. "No, sir, but he went on foot," answered the butler. "I let him out--he turned up Paddington way." "You didn't notice anything out of the common about him?" suggested Purdie. The butler hesitated for a moment. "Well, sir," he said at last, "I did notice something. Come this way, Mr. Purdie." Turning away from the hall, he led Purdie through the library in which Levendale had received Ayscough and his companions into a small room that opened out of it. Purdie, looking round him, found that he was standing in a laboratory, furnished with chemical apparatus of the latest descriptions. Implements and appliances were on all sides; there were rows of bottles on the shelves; a library of technical books filled a large book-case; everything in the place betokened the pursuit of a scientific investigator. And Purdie's keen sense of smell immediately noted the prevalent atmosphere of drugs and chemicals. "It was here that I saw Mr. Levendale last night, sir," said the butler. "He called me in. He was measuring something from one of those bottles into a small phial, Mr. Purdie--he put the phial in his waistcoat pocket. Look at those bottles, sir--you'll see they all contain poison!--you can tell that by the make of 'em." Purdie glanced at the shelf which the butler indicated. The bottles ranged on it were all of blue glass, and all triangular in shape, and each bore a red label with the word _Poison_ prominently displayed. "Odd!" he said. "You've some idea?" he went on, looking closely at the butler. "Something on your mind about this? What is it?" The butler shook his head. "Well, sir," he answered, "when you see a gentleman measuring poison into a phial, which he carefully puts in his pocket, and when he goes out, and when he never comes back, and when you can't hear of him, anywhere! why, what are you to think? Looks strange, now, doesn't it, Mr. Purdie?" "I don't know Mr. Levendale well enough to say," replied Purdie. "There may be some quite good reason for Mr. Levendale's absence. He'd no trouble of any sort, had he?"