We laid our burden upon the surgery table.

“You will want to make an examination, Petrie,” said Smith in his decisive way, “and the officer here might ’phone for the ambulance.  I have some investigations to make also.  I must have the pocket lamp.”

He raced upstairs to his room, and an instant later came running down again.  The front door banged.

“The telephone is in the hall,” I said to the constable.

“Thank you, sir.”

He went out of the surgery as I switched on the lamp over the table and began to examine the marks upon Forsyth’s skin.  These, as I have said, were in groups and nearly all in the form of elongated punctures; a fairly deep incision with a pear-shaped and superficial scratch beneath it.  One of the tiny wounds had penetrated the right eye.

The symptoms, or those which I had been enabled to observe as Forsyth had first staggered into view from among the elms, were most puzzling.  Clearly enough, the muscles of articulation and the respiratory muscles had been affected; and now the livid face, dotted over with tiny wounds (they were also on the throat), set me mentally groping for a clue to the manner of his death.

No clue presented itself; and my detailed examination of the body availed me nothing.  The gray herald of dawn was come when the police arrived with the ambulance and took Forsyth away.

I was just taking my cap from the rack when Nayland Smith returned.

“Smith!” I cried—­“have you found anything?”

He stood there in the gray light of the hallway, tugging at the lobe of his left ear, an old trick of his.

The bronzed face looked very gaunt, I thought, and his eyes were bright with that febrile glitter which once I had disliked, but which I had learned from experience were due to tremendous nervous excitement.  At such times he could act with icy coolness and his mental faculties seemed temporarily to acquire an abnormal keenness.  He made no direct reply; but—­

“Have you any milk?” he jerked abruptly.

So wholly unexpected was the question, that for a moment I failed to grasp it.  Then—­

“Milk!” I began.

“Exactly, Petrie!  If you can find me some milk, I shall be obliged.”

I turned to descend to the kitchen, when—­

“The remains of the turbot from dinner, Petrie, would also be welcome, and I think I should like a trowel.”

I stopped at the stairhead and faced him.

“I cannot suppose that you are joking, Smith,” I said, “but—­”

He laughed dryly.

“Forgive me, old man,” he replied.  “I was so preoccupied with my own train of thought that it never occurred to me how absurd my request must have sounded.  I will explain my singular tastes later; at the moment, hustle is the watchword.”

Evidently he was in earnest, and I ran downstairs accordingly, returning with a garden trowel, a plate of cold fish and a glass of milk.