The body lay prone upon the deal table—­this latest of the river’s dead—­ dressed in rough sailor garb, and, to all outward seeming, a seaman of nondescript nationality—­such as is no stranger in Wapping and Shadwell.  His dark, curly hair clung clammily about the brown forehead; his skin was stained, they told me.  He wore a gold ring in one ear, and three fingers of the left hand were missing.

“It was almost the same with Mason.”  The river police inspector was speaking.  “A week ago, on a Wednesday, he went off in his own time on some funny business down St. George’s way—­and Thursday night the ten-o’clock boat got the grapnel on him off Hanover Hole.  His first two fingers on the right hand were clean gone, and his left hand was mutilated frightfully.”

He paused and glanced at Smith.

“That lascar, too,” he continued, “that you came down to see, sir; you remember his hands?”

Smith nodded.

“He was not a lascar,” he said shortly.  “He was a dacoit.”

Silence fell again.

I turned to the array of objects lying on the table—­those which had been found in Cadby’s clothing.  None of them were noteworthy, except that which had been found thrust into the loose neck of his shirt.  This last it was which had led the police to send for Nayland Smith, for it constituted the first clew which had come to light pointing to the authors of these mysterious tragedies.

It was a Chinese pigtail.  That alone was sufficiently remarkable; but it was rendered more so by the fact that the plaited queue was a false one being attached to a most ingenious bald wig.

“You’re sure it wasn’t part of a Chinese make-up?” questioned Weymouth, his eye on the strange relic.  “Cadby was clever at disguise.”

Smith snatched the wig from my hands with a certain irritation, and tried to fit it on the dead detective.

“Too small by inches!” he jerked.  “And look how it’s padded in the crown.  This thing was made for a most abnormal head.”

He threw it down, and fell to pacing the room again.

“Where did you find him—­exactly?” he asked.

“Limehouse Reach—­under Commercial Dock Pier—­exactly an hour ago.”

“And you last saw him at eight o’clock last night?”—­to Weymouth.

“Eight to a quarter past.”

“You think he has been dead nearly twenty-four hours, Petrie?”

“Roughly, twenty-four hours,” I replied.

“Then, we know that he was on the track of the Fu-Manchu group, that he followed up some clew which led him to the neighborhood of old Ratcliff Highway, and that he died the same night.  You are sure that is where he was going?”

“Yes,” said Weymouth; “He was jealous of giving anything away, poor chap; it meant a big lift for him if he pulled the case off.  But he gave me to understand that he expected to spend last night in that district.  He left the Yard about eight, as I’ve said, to go to his rooms, and dress for the job.”