“I think we’ll sit down,” said the engineer. “It’s going to take a little while to explain the matter.”
He indicated three seats and brought a small table over, so that they could all see the document which he placed on it.
“In the first place,” he began, “you once told us that your grandfather had mechanical leanings—he’d invented some kind of geared bicycle. That didn’t strike me at the time, particularly; but as it came back to some purpose later on, I mention it first. On the same evening, by pure chance, I happened to notice these little holes at the corners of the squares of the Chess-board on the pavement here. These things, I mean.”
He rose and pointed out one or two of them.
“When you told us that the Talisman was safe, I must confess I thought of a man-trap. The holes in the pavement suggested some kind of machinery needing lubrication; and I had some notion of a trap-door which would open when the Talisman was touched and so trap a thief. That was an entirely mistaken idea, as you told us yourself. Still, at the back of my mind I had connected these oil-holes with the presence of some machinery or other and with the mechanical tastes of your grandfather.”
The distrust had passed completely away from Rollo’s face. He was now listening with obvious eagerness to Westenhanger’s explanation.
“The next thing was, of course, your showing us these things from the safe. They were quite meaningless to me then.”
He lifted them lightly and put them back on the table.
“The next bit’s hard to account for. Somehow I got a feeling that the document was the key to some problem or other, and I asked you to let me copy it. It was just an impulse. I really can’t say what I expected to do with it. It certainly wasn’t mere vulgar curiosity to dig out the Dangerfield Secret.”
Again a flicker of distrust crossed Rollo’s face. Westenhanger saw it.