Shelley nodded, and examined the headstone above the grave at which they had halted.

“That’s it,” he said briefly. “Carry on.”

But before they had had time to start, another man approached.

“Sorry I’m late, Shelley,” he said as he drew near. “Couldn’t get here earlier. Had a troublesome case to get through. I rushed it as well as I could, but it just couldn’t be done any sooner.”

“I was wondering where you were, old man,” Shelley murmured. “Still, you’re in good time. This is Dr. Maguire, gentlemen,” he explained. “Dr. Maguire is a pathologist, and will shortly be making a post-mortem examination of the late Professor Wilkinson. I thought it well that he should be here to make a more or less cursory examination of the body on its first exhumation, in case there were any symptoms obvious which would disappear in the time which must elapse before the full post-mortem is to be made.”

Now the two men with spades set to with a will, first removing the turf from over the grave, then digging down into the rich brown earth beneath. They had placed their lanterns on the ground, and the flickering light from these was now more ghastly than ever. Shining unsteadily upward in the gloom, the little slice of unsteady light made the surrounding darkness seem blacker than before.

Henry found himself peering myopically into the distance, vainly trying to pierce the veil of dreary gloom that shut them in, that made this little group of men almost a world on their own, cut off from the warm friendliness of the outside universe. Again he shuddered as he heard the sudden rattle of one of the spades against a large stone in the ground. He stood on his toes and peered over the shoulder of the Home Office official at the two men who were still digging steadily on.

There was still, however, nothing to be seen. The earth came steadily up, spadeful by spadeful, and there was now a considerable heap accumulated beside the open grave. And still the men dug on. And still Henry peered at the diggers, wondering if in their minds there was any trace of nausea at the gruesome task which was theirs to perform. He supposed not. Presumably grave-diggers grew accustomed to their unpleasant association with man’s mortality. For a moment Henry tried to picture himself as a grave-digger, but his imagination boggled at the task.

Then there came a sharp hiss of indrawn breath from Shelley. The Scotland Yard man, outwardly calm, was filled with excitement. This might well be the final link in a chain of unmistakable evidence—a chain leading to the scaffold.