"Don't I? Well, I do, though. Of course I don't mean there's really a combination lock. That would never do. We often have to open the coffin for a friend who wants to see the dead face again, or for folks that come to the funeral late. It's funny, when you come to think of it, how folks will be late to funerals. As they only have this last visit to make, you'd think they'd make it a point to be on time and not delay the funeral. But about the way I fasten a coffin. If any grave-robber tackles one of my coffins without knowing the trick, he'd be astonished, I tell you. I often think of it and laugh. You see, there's a dozen screws and they look just like ordinary screws. But if you work them all out with a screw-driver, your coffin lid is just as tight as ever. You see, it's this way. The real screw works with a reverse thread, and is hollow on the top. Now I have a screw-driver that is really a screw. When the screw-threaded end of this is screwed into the hollow end of the coffin-bolt, as soon as it is in tight it begins to unscrew the bolt. To put the bolt in, in the first place, I first screw it tight on to my screw-driver, and then drive it in, turning backwards, and as soon as it is tight my screw-driver begins to unscrew and so comes out. Then I drop in my dummy screw, and just turn it down to fill the hole. Now the dummy screw and the reverse thread of the real bolt is a puzzle for a grave-robber, and anyway he couldn't solve it without one of my own tools."
Mr. Barnes reflected deeply upon this as a most important statement. If Mr. Quadrant's coffin was thus fastened, no one could have opened it without the necessary knowledge and the special screw-driver. He recalled that the butler had told him that one of Mr. Berial's men had been at the house after the departure of the others. This man was therefore in the position to have opened the coffin, supposing that he had had one of the screw-drivers. Of this it would be well to learn.
"I suppose," said Mr. Barnes, "that the coffin in which you placed Mr. Quadrant was fastened in this fashion?"
"Yes; and I put the lid on and fastened it myself."
"What, then, did you do with the screw-driver? You might have left it at the house."
"I might have, but I didn't. No; I'm not getting up a combination and then leaving the key around loose. No, sir; there's only one of those screw-drivers, and I take care of it myself. I'll show it to you."
The old man went to a drawer, which he unlocked, and brought back the tool.
"You see what it is," he continued—"double-ended. This end is just the common every-day screw-driver. That is for the dummies that fill up the hollow ends after the bolts are sent home. The other end, you see, looks just like an ordinary screw with straight sides. There's a shoulder to keep it from jamming. Now that's the only one of those, and I keep it locked in that drawer with a Yale lock, and the key is always in my pocket. No; I guess that coffin wasn't opened after I shut it."
Mr. Barnes examined the tool closely, and formed his own conclusions, which he thought best to keep to himself.
"Yes," said he aloud; "it does seem as though the mistake must be in the identification."