Ludlow's pistols in his belt, and a thick stick
in his hand, kept watch--walking up and down the passages, and into all
the empty rooms, and should he see anything he was immediately to call
the captain and the rest of the gentlemen. Once, as he was walking
slowly along a passage on the basement story, he saw on the ceiling a
faint gleam of light, as if it had been cast from somewhere below, but
as he proceeded it vanished, and though he looked about carefully he
could not discover the spot whence it had come. He however noted it,
that he might prosecute his examination in the morning. He was walking
on, when a deep groan came from almost beneath his feet, as it seemed.
Tom was not altogether free from superstition, but though he did not
disbelieve in ghosts and other foolish notions, he was too brave to be
frightened by anything, and consequently cool and capable of reflection.

"Ho! ho!" he thought, "if that was a ghost which groaned, he has got a
light to light himself about with anyhow; and he must be stowed away in
some hollow hereabouts, under the floor or in the wall, and there he
shall remain till morning light if he doesn't want a broken head or an
ounce of lead sent through his body." So he posted himself in the
passage to watch the place whence the sound had come. After waiting for
some time he took a short turn, when directly his footsteps sounded
along the passage there was another groan. "Ho! ho! old mate," he
muttered, not aware that Hamlet had used the expression before him;
"groan away as much as you like, you'll find it a tough job to work your
way through the hard rock, I suspect, and I'm not going to let you
frighten me away from my post, let me tell you; the pistol has got a
bullet in it this time, understand."

The ghost evidently considered discretion the best part of valour, for
after this not a groan or any other sound was heard. Tom watched all
the night, hoping that somebody or something might appear, that he might
get a shot at it; but not even a mouse crept out of its hole, nor were
the inmates of the Tower again disturbed. Everybody was on foot at an
early hour, and the old Tower was thoroughly examined inside and out,
but no possible way by which the visitors could have entered could be
discovered.

Tom's account of his having seen a light and heard a groan was
disbelieved; it was thought that his imagination had deceived him.
"Maybe it did," muttered Tom to himself, "howsomdever