“You think it was the Doctor himself?”

“It seems possible.  Who else has eyes like the eyes Miss Eltham saw from the window last night?”

Then remains to tell the nature of the outrage whereby Fu-Manchu had planned to prevent Eltham’s leaving England for China.  This we learned from Denby.  For Denby was not dead.

It was easy to divine that he had stumbled upon the fiendish visitor at the very entrance to his burrow; had been stunned (judging from the evidence, with a sand-bag), and dragged down into the cache—­to which he must have lain in such dangerous proximity as to render detection of the dummy bush possible in removing him.  The quickest expedient, then, had been to draw him beneath.  When the search of the shrubbery was concluded, his body had been borne to the edge of the bushes and laid where we found it.

Why his life had been spared, I cannot conjecture, but provision had been made against his recovering consciousness and revealing the secret of the shrubbery.  The ruse of releasing the mastiff alone had terminated the visit of the unbidden guest within Redmoat.

Denby made a very slow recovery; and, even when convalescent, consciously added not one fact to those we already had collated; his memory had completely deserted him!

This, in my opinion, as in those of the several specialists consulted, was due, not to the blow on the head, but to the presence, slightly below and to the right of the first cervical curve of the spine, of a minute puncture—­undoubtedly caused by a hypodermic syringe.  Then, unconsciously, poor Denby furnished the last link in the chain; for undoubtedly, by means of this operation, Fu-Manchu had designed to efface from Eltham’s mind his plans of return to Ho-Nan.

The nature of the fluid which could produce such mental symptoms was a mystery—­a mystery which defied Western science:  one of the many strange secrets of Dr. Fu-Manchu.

CHAPTER X

Since Nayland Smith’s return from Burma I had rarely taken up a paper without coming upon evidences of that seething which had cast up Dr. Fu-Manchu.  Whether, hitherto, such items had escaped my attention or had seemed to demand no particular notice, or whether they now became increasingly numerous, I was unable to determine.

One evening, some little time after our sojourn in Norfolk, in glancing through a number of papers which I had brought in with me, I chanced upon no fewer than four items of news bearing more or less directly upon the grim business which engaged my friend and I.

No white man, I honestly believe, appreciates the unemotional cruelty of the Chinese.  Throughout the time that Dr. Fu-Manchu remained in England, the press preserved a uniform silence upon the subject of his existence.  This was due to Nayland Smith.  But, as a result, I feel assured that my account of the Chinaman’s deeds will, in many quarters, meet with an incredulous reception.