A slight noise disturbed these unpleasant reveries.  It was nothing less than the rattling of keys!

For a moment I wondered if I had heard aright, or if the sound portended the coming of some servant of the doctor, who was locking up the establishment for the night.  The jangling sound was repeated, and in such a way that I could not suppose it to be accidental.  Some one was deliberately rattling a small bunch of keys in an adjoining room.

And now my heart leaped wildly—­then seemed to stand still.

With a low whistling cry a little gray shape shot through the doorway by which Fu-Manchu had retired, and rolled, like a ball of fluff blown by the wind, completely under the table which bore the weird scientific appliances of the Chinaman; the advent of the gray object was accompanied by a further rattling of keys.

My fear left me, and a mighty anxiety took its place.  This creature which now crouched chattering at me from beneath the big table was Fu-Manchu’s marmoset, and in the intervals of its chattering and grimacing, it nibbled, speculatively, at the keys upon the ring which it clutched in its tiny hands.  Key after key it sampled in this manner, evincing a growing dissatisfaction with the uncrackable nature of its find.

One of those keys might be that of the handcuffs!

I could not believe that the tortures of Tantulus were greater than were mine at this moment.  In all my hopes of rescue or release, I had included nothing so strange, so improbable as this.  A sort of awe possessed me; for if by this means the key which should release me should come into my possession, how, ever again, could I doubt a beneficent Providence?

But they were not yet in my possession; moreover, the key of the handcuffs might not be amongst the bunch.

Were there no means whereby I could induce the marmoset to approach me?

Whilst I racked my brains for some scheme, the little animal took the matter out of my hands.  Tossing the ring with its jangling contents a yard or so across the carpet in my direction, it leaped in pursuit, picked up the ring, whirled it over its head, and then threw a complete somersault around it.  Now it snatched up the keys again, and holding them close to its ear, rattled them furiously.  Finally, with an incredible spring, it leaped onto the chain supporting the lamp above my head, and with the garish shade swinging and spinning wildly, clung there looking down at me like an acrobat on a trapeze.  The tiny, bluish face, completely framed in grotesque whiskers, enhanced the illusion of an acrobatic comedian.  Never for a moment did it release its hold upon the key-ring.

My suspense now was intolerable.  I feared to move, lest, alarming the marmoset, it should run off again, taking the keys with it.  So as I lay there, looking up at the little creature swinging above me, the second wonder of the night came to pass.