“Did you know it was a poisoned watch?” asked Jack Young.

“I had guessed that after what happened, and that is why I warned Donovan to be careful.  But, as I said, I thought it was like a sword cane or a spring dagger—­that only pressure on a certain part was needed to force out the needle with its death-carrying smear of some subtle Indian poison.  I never dreamed it was like an alarm clock.”

“Well, it was,” said Mr. Kettridge.  “I can easily see all the parts, now that I have taken it apart, and the time-setting arrangement is very compact, simple and effective.”

“You were careful not to scratch yourself on the needle?” asked the colonel quickly.

“Oh, yes indeed!  I took that out first.  But do you think, Colonel, in spite of what I have said about Jimmie not knowing how this watch operated, and, presumably, not having done any work on it—­do you think he can have planned to kill Mrs. Darcy with it?”

“Hardly.  And yet it is possible that Mrs. Darcy may have been killed by the watch.”

“Killed by it?—­how?” gasped Jack Young.  “I thought she was stabbed, and her skull fractured.”

“She had both those injuries, it is true.  But what is to have prevented her from having been punctured by the watch just before she received those hurts?

“I mean in this way,” went on the colonel.  “We will assume that Singa Phut, finding some trifling thing the matter with his devilish watch, brought it to the Darcy shop, where he was fairly well known.

“Darcy promised to fix the timepiece but neglected or forgot to do it, leaving it on his table.  Then, remembering it early in the morning—­perhaps feeling guilty at having spent part of the night working on his electric lathe—­he got up to do as he had promised, and—­”

“Finds his cousin dead!” interrupted Mr. Kettridge.

“So he says!” added Jack Young significantly.

“Well, we won’t go into that,” observed the colonel.  “I was going to make another point.  Leaving Darcy out of it, and assuming that he had left the watch on his table intending to get up in the morning and fix it, what is to have prevented Mrs. Darcy from coming down to her store—­say, before midnight, after Darcy left her.

“She saw the watch on the table, and, picking it up, may have wound it.  This set in motion the death-dealing mechanism, and her hand may have been punctured with the poison.”

“But, even then,” put in Young, as he puffed out another cloud of smoke, “if the poison from the watch killed her, why would any one strike her on the head and stab her?”

“That may have occurred just after her hand was punctured by the needle of the watch,” said the detective, “and before the poison had time to work.  It is not instantaneous.”

“But who would have struck or stabbed her after that?” asked Mr. Kettridge.  “I mean, of course, leaving Jimmie out, for I don’t believe he did it.”