“Some one planned here to kill Shirley, get him out of the way,” reconstructed Kennedy, gazing about; “some one working under the cloak of Oriental religion.”

“Mrs. Anthony?” queried Grady.  Kennedy shook his head.

“On the contrary, like Shirley, she was an agent of the Indian Secret Service.  The rest of the cipher shows it.  She was sent to watch some one else, as he was sent to watch Mrs. Rogers.  Neither could have known that the other was on the case.  She found out, first, that the package with the prayer-bean and the word ‘Gadhr’ was an attempt to warn and save Shirley, whom she had known in Calcutta and still loved, but feared to compromise.  She must have tried to see him, but failed.  She hesitated to write, but finally did.  Then some one must have seen that she was dangerous.  Another poisoned bomb was sent to her.  No; the nautch-girl is innocent.”

“’Sh!” cautioned Grady.

Outside we could hear the footsteps of some one coming along the hall.  Kennedy snapped off his light.  The door opened.

“Stand still!  One motion and I will throw it!”

As Kennedy’s voice rang out from the direction of the table on which stood the half-finished glass bombs, Grady and I flung ourselves forward at the intruder, not knowing what we would encounter.

A moment later Kennedy had found the electric switch and flashed up the lights.

It was Singh, who had used both Mrs. Rogers’s money and Raimanandra’s religion to cover his conspiracy of revolt.

V

THE PHANTOM DESTROYER

“Guy Fawkes himself would shudder in that mill.  Think of it—­five explosions on five successive days, and not a clue!”

Our visitor had presented a card bearing the name of Donald MacLeod, chief of the Nitropolis Powder Company’s Secret Service.  It was plain that he was greatly worried over the case about which he had at last been forced to consult Kennedy.

As he spoke, I remembered having read in the despatches about the explosions, but the accounts had been so meager that I had not realized that there was anything especially unusual about them, for it was at the time when accidents in and attacks on the munitions-plants were of common occurrence.

“Why,” went on MacLeod, “the whole business is as mysterious as if there were some phantom destroyer at work!  The men are so frightened that they threaten to quit.  Several have been killed.  There’s something strange about that, too.  There are ugly rumors of poisonous gases being responsible, quite as much as the explosions, though, so far, I’ve been able to find nothing in that notion.”

“What sort of place is it?” asked Kennedy, interested at once.

“Well, you see,” explained MacLeod, “since the company’s business has increased so fast lately, it has been forced to erect a new plant.  Perhaps you have heard of the Old Grove Amusement Park, which failed?  It’s not far from that.”