Kneeling there and looking into his upturned eyes, I became aware that my position was not an enviable one, particularly since I felt little disposed to set the law on the track of the real culprit.  For this man who now lay dead at my feet was doubtless one of the pair who had attempted the life of the fireman of the Jupiter.

That my seafaring acquaintance had designed to kill the Chinaman I did not believe, despite his stormy words:  the death had been an accident, and (perhaps my morality was over-broad) I considered the assault to have been justified.

Now my ideas led me further yet.  The dead Chinaman wore a rough blue coat, and gingerly, for I found the contact repulsive, I inserted my hand into the inside pocket.  Immediately my fingers closed upon a familiar object—­and I stood up, whistling slightly, and dangling in my left hand the missing pigtail!

Beyond doubt Justice had guided the seaman’s blows.  This was the man who had murdered my dark-eyed visitor!

I stood perfectly still, directing the little white ray of my flashlight upon the pigtail in my hand.  I realized that my position, difficult before, now was become impossible; the possession of the pigtail compromised me hopelessly.  What should I do?

“My God!” I said aloud, “what does it all mean?”

“It means,” said a gruff voice, “that it was lucky I was following you and saw what happened!”

I whirled about, my heart leaping wildly.  Detective-Sergeant Durham was standing watching me, a grim smile upon his face!

I laughed rather shakily.

“Lucky indeed!” I said.  “Thank God you’re here.  This pigtail is a nightmare which threatens to drive me mad!”

The detective advanced and knelt beside the crumpled-up figure on the ground.  He examined it briefly, and then stood up.

“The fact that he had the missing pigtail in his pocket,” he said, “is proof enough to my mind that he did the murder.”

“And to mine.”

“There’s another point,” he added, “which throws a lot of light on the matter.  You and Mr. Harley were out of town at the time of the Huang Chow case; but the Chief and I outlined it, you remember, one night in Mr. Harley’s rooms?”

“I remember it perfectly; the giant spider in the coffin------”

“Yes; and a certain Ah Fu, confidential servant of the old man, who used to buy the birds the thing fed on.  Well, Mr. Knox, Huang Chow was the biggest dealer in illicit stuff in all the East End—­and this battered thing at our feet is—­Ah Fu!”

“Huang Chow’s servant?”

“Exactly!”

I stared, uncomprehendingly, and: 

“In what way does this throw light on the matter?” I asked.

Durham—­a very intelligent young officer—­smiled significantly.

“I begin to see light!” he declared.  “The gentleman who made off just as I arrived on the scene probably had a private quarrel with the Chinaman and was otherwise not concerned in any way.”