“I can’t tell you much,” answered Rhona. “He was out most of the day, and generally by himself. I was only out with him twice—once when we went to do some shopping, another time when we called on Mr. Kenthwaite at his rooms in the Temple. I understood he was looking for a house—seeing house agents and so on. He was out morning, afternoon and evening.”
“Did he never tell you anything about where he’d been, or whom he’d seen?”
“No. He was the sort of man who keeps things to himself. I have no idea where he went nor whom he saw.”
“Didn’t say anything about where he was going last night?”
“No. He only said that he was going out and that I should find him here when I got back from the theatre, to which I was going with Mrs. Keeley. We got back here soon after eleven. But he hadn’t come in—as you know.”
“You never heard him speak of having enemies?”
“I should think he hadn’t an enemy in the world! He was a very kind man and very popular, even with the people he had to deal with as a police-superintendent.”
“And I suppose he’d no financial worries—anything of that sort? Nor any other troubles—nothing to bother him?”
“I don’t think he’d a care in the world,” said Rhona confidently. “He was looking forward with real zest to settling down in London. And as to financial worries, he’d none. He was well off.”
“Always a saving, careful man,” remarked Mrs. Keeley. “Oh, yes, quite well off—apart from his pension.”
Matherfield glanced at Hetherwick, who had listened carefully to all that was asked and answered. Something in the glance seemed to invite him to take a hand.
“This occurs to me,” said Hetherwick. He turned to Rhona. “Apart from this house-hunting, do you know whether your grandfather had any business affair in hand in London? What I’m thinking of is this—from what I saw of him in the train, he appeared to be an active, energetic man, not the sort of man who, because he’d retired, would sit down in absolute idleness. Do you know of anything that he thought of undertaking—any business he thought of joining?”
Rhona considered this question for a while.
“Not any business,” she replied at last. “But there is something that may have to do with what you suggest. My grandfather had a hobby. He experimented in his spare time.”
“What in?” asked Hetherwick. Then he suddenly remembered the stained fingers that he had noticed on the hands of both men the night before. “Was it chemicals?” he added quickly.
“Yes, in chemicals,” she answered with a look of surprise. “How did you know that?”
“I noticed that his hands and fingers were stained,” replied Hetherwick. “So were those of the man he was with. Well—but this something?”
“He had a little laboratory in our garden at Sellithwaite,” she continued. “He spent all his spare time in it—he’d done that for years. Lately, I know, he’d been trying to invent or discover something—I don’t know what. But just before we left Sellithwaite, he told me that he’d solved the problem, and when he was sorting out and packing up his papers he showed me a sealed envelope in which he said were the particulars of his big discovery—he said there was a potential fortune in it and that he should die a rich man. I saw him put that envelope in a pocketbook which he always carried with him.”
“That would be the pocketbook I examined last night,” said Matherfield. “There was no sealed envelope, nor one of which any seal had been broken, in that. There was nothing but letters, receipts and unimportant papers.”
“It is not in his other pocketbooks,” declared Rhona. “I went through all his things myself very early this morning—through everything that he had here. I know that he had that envelope yesterday—he pulled out some things from his pocket when we were lunching with Mr. Kenthwaite in a restaurant in Fleet Street, and I saw the envelope. It was a stout, square envelope, across the front of which he had drawn two thick red lines, and it was heavily sealed with black sealing-wax at the back.”
“That was yesterday, you say?” asked Matherfield sharply. “Yesterday noon? Just so! Then as he had it yesterday at noon, and as it wasn’t in his pockets last night and is not among his effects in this house, it’s very clear that between, say, two o’clock yesterday and midnight he parted with it. Now then, to whom? That’s a thing we’ve just got to find out! But you’re sure he wasn’t joking when he told you that this discovery, or invention, or whatever it was, was worth a potential fortune?”
“On the contrary, he was very serious,” replied Rhona. “Unusually serious for him. He wouldn’t tell me what it was, nor give me any particulars—all he said was that he’d solved a problem and hit on a discovery that he’d worked over for years, and that the secret was in that envelope and worth no end of money. I asked him what he meant by no end of money and he said: ‘Well, at any rate, a hundred thousand pounds—in time.’ ”
The two men exchanged glances; silence fell on the whole group.
“Oh!” said Matherfield at last. “A secret worth a hundred thousand pounds—in time. This will have to be looked into—narrowly. What do you think, Mr. Hetherwick?”
“Yes,” answered Hetherwick. “You’ve no idea, of course, as to whether your grandfather had done anything about putting this discovery on the market—or made any arrangement about selling it? No! Well, can you tell me this: What sort of house did your grandfather want to rent here in London? I mean, do you know what rent he was prepared to pay?”
“I can answer that,” remarked Mrs. Keeley. “He told me he wanted a good house—a real good one—in a convenient suburb, and he was willing to go
