The more I thought of it the angrier I grew, and I had to get up and move about the room. I tried the shutters, but they were the kind that lock with a key, and I couldn’t move them. From the outside came the faint clucking of hens in the warm sun. Then I groped among the sacks and boxes. I couldn’t open the latter, and the sacks seemed to be full of things like dog-biscuits that smelt of cinnamon. But, as I circumnavigated the room, I found a handle in the wall which seemed worth investigating.

It was the door of a wall cupboard⁠—what they call a “press” in Scotland⁠—and it was locked. I shook it, and it seemed rather flimsy. For want of something better to do I put out my strength on that door, getting some purchase on the handle by looping my braces round it. Presently the thing gave with a crash which I thought would bring in my warders to inquire. I waited for a bit, and then started to explore the cupboard shelves.

There was a multitude of queer things there. I found an odd vesta or two in my trouser pockets and struck a light. It was out in a second, but it showed me one thing. There was a little stock of electric torches on one shelf. I picked up one, and found it was in working order.

With the torch to help me I investigated further. There were bottles and cases of queer-smelling stuffs, chemicals no doubt for experiments, and there were coils of fine copper wire and yanks and yanks of thin oiled silk. There was a box of detonators, and a lot of cord for fuses. Then away at the back of the shelf I found a stout brown cardboard box, and inside it a wooden case. I managed to wrench it open, and within lay half a dozen little grey bricks, each a couple of inches square.

I took up one, and found that it crumbled easily in my hand. Then I smelt it and put my tongue to it. After that I sat down to think. I hadn’t been a mining engineer for nothing, and I knew lentonite when I saw it.