“But both of them had their heads smashed in!”

“Yes, Jack.”

“But, Great Scott, Colonel! the watch can’t do that as well as poison to death!  It’s out of the question!”

“Of course it is.  I didn’t claim the watch did anything like that.  I don’t even claim the poison-needle watch killed Mrs. Darcy or Shere Ali.  But that it did kill Chet I’m certain.”

“I believe you’re right there, Colonel Ashley.  Poor little dog!” and Jack, who loved animals, looked at the limp body.

“I know I’m right, Jack.  If I had seen, in time, that he had the watch I’d have tried to get it away from him.  But maybe it will turn out for the best.  In the interests of justice—­”

“Do you think this will help in solving the mystery?”

“It may.”

“But I thought you said the poison-needle watch might not have killed Mrs. Darcy?”

“I’m not saying anything, Jack.  It might, and might not.”

“But the blow on her head—­the stab wound in her side—?”

“Both could have been inflicted after the poison watch killed her—­if it did.  Mind you, Jack, I’m making no statements.  I am only suggesting possibilities.”

“But—­ Great Scott, Colonel—­Shere Ali was killed in the same way!  He had the ticking watch in his hand, and his head was smashed in!”

“Yes.”

“And of course he may have been struck on his head after he died from the poisoned watch?”

“Exactly.”

“And this watch Darcy had in his possession to repair just before Mrs. Darcy was found dead, and she had it in her hand and—­say, Colonel, where are we at?” and Jack Young looked hopelessly at his chief.

“I don’t know,” was the measured answer.  “I wish I did.  There is only one thing we can be sure of, and that is, no matter what part Darcy had in the murder—­if he had any—­by means of this watch in the case of Mrs. Darcy, he had none in Shere Ali’s case, for Darcy was locked up when that tragedy occurred.”

“That’s so, Colonel.  And yet—­ Oh, well, what’s the use of speculating?  What are you going to do next?”

“I don’t know.  I wish—­”

There came another knock on the door and a voice asked: 

“Is Chet in here, Colonel?  I generally find him with you when he isn’t in my room and—­”

Mr. Bland entered through the opened door, and from the figures of the detective and his helper the eyes of Chet’s owner went to that of the motionless dog.  Chet’s master sensed something wrong, for with a cry of his pet’s name he hurried toward the stretched-out animal.

“Don’t!” exclaimed the colonel, reaching out a restraining hand.  “The dog has been poisoned, and with a poison so deadly that even some of the foam from his lips, in a tiny scratch, might cause your death.  Don’t touch him with bare hands.”

“Poisoned, Colonel!  Chet poisoned?”