at least three hours, although it seemed
to him only as many minutes, when he suddenly started broad awake, with
the disagreeable feeling that he was no longer alone, or rather, to put
it more exactly, that someone had that instant stealthily entered his
room by way of the window, which, as is customary in Cuba, had been left
wide open for the admission of every possible breath of air.

For a moment he lay perfectly still, listening intently, and peering the
while into the darkness which encompassed him. All was perfectly still,
however, save for the faint rustle in the night breeze of the mosquito
curtains which surrounded his bed, and the musical tinkling of the
waters of the fountain outside; while the darkness was so intense that
it was only with the utmost difficulty he could dimly discern the
opening of the window, which, it will be remembered, looked out upon a
patio, or kind of courtyard. Suddenly the room was faintly illumined
for a moment by a flicker of summer lightning, and Jack felt almost
positive that during that fraction of a second he caught a glimpse of
something by the open window which had certainly not been there when he
retired for the night--something which suggested a crouching human
figure. Stretching out his hand, Jack cautiously and noiselessly parted
the mosquito curtains, with the object of getting a clear view when the
next flash should come, as come he knew it would. And come it did, a
minute or two later, disclosing to the young man's astonished gaze a
form on hands and knees, about halfway between the window and the bed.
As before, the glimmer of the lightning was but momentary, but, brief as
it was, it sufficed Jack to see that the individual, whoever he might
be, held a long, murderous-looking knife in his right hand; and the
inference was obvious that he was there for no good purpose. Jack had
learned, among other things, to act promptly and with decision, and no
sooner was he again in darkness than, with a single bound, he was on his
feet on the floor, where he instantly came into violent collision with
the stranger, who was at that precise moment in the very act of rising
from his knees. Brief as had been the flicker of the lightning, it had
enabled Jack to measure his distance and to note the exact spot occupied
by the unknown: the moment, therefore, that he came into contact with
the intruder his left hand fell unerringly upon the right wrist of the
other, which he seized in