mptied, as its
escape was cut off.

[Illustration: "Struck it a terrific blow with the boat-hook."
A Master of Mysteries.--Page 167]

Each of the following minutes seemed stretched into a lifetime as, with
eyes riveted on the dark water in the lock, I watched its gradual
descent. I hardly dared to think of what I expected to see rise to the
surface any moment. Would the lock never empty? Down, down sank the
level, and still I saw nothing. A long, misshapen arm of black cloud was
slowly stretching itself across the moon.

Hark! there was something moving about down in the well of darkness
below me, and as I stood and watched I saw that the water was uncovering
a long, black mass and that something ran slowly out of the water and
began to clamber up the slimy, slippery beams. What in the name of
heaven could it be? By the uncertain light I could only see its dim
outline; it seemed to have an enormous bulbous head and dripping,
glistening body. The sound of a rapid patter up the tow-path told me
that the old man had seen it and was running for his life.

I rushed down to where the thing was, and as its great head appeared
above the edge, with all my force struck it a terrific blow with the
boat-hook. The weapon flew into splinters in my hand, and the next
moment the creature had leapt up beside me and dashed me to the ground
with almost superhuman force. I was up and on to it again in a second,
and as I caught and closed with it saw that I had at least to deal with
a human being, and that what he lacked in stature he more than made up
for in strength. The struggle that ensued was desperate and furious. The
covering to his head that had splintered the boat-hook was, I saw, a
sort of helmet, completely protecting the head from any blow, and the
body was cased in a slippery, closely fitting garment that kept eluding
my grasp. To and fro we swayed and wrestled, and for a moment I thought
I had met my match till, suddenly freeing my right arm, I got in a
smashing blow in the region of the heart. The creature uttered a cry of
pain and fell headlong to the ground.

Old Jimmy Pegg had hurried back as soon as he heard our struggles and
knew that he was not dealing with a being of another world. He ran up
eagerly to me.

"Here's your ghost, you old coward!" I panted; "he has got the hardest
bone and muscle I ever felt in a ghost yet. I am not used to fighting
men in helmets, and he is as slippery as an eel, but I hope to good