occupied the topmost third of the case, which was of thick plate-glass
bound and backed with gilt metal. There was no apparent means of opening
the case. From what one could see, however, the workmanship was perfect,
exquisite. The compensating pendulum alone was ornamented--with a
conventional sun in diamonds, and one could imagine the effect when it
swung in brilliant light. At present it was at rest, held up to the right
wall of the case by a loop of fine silk passed through a minute hole in
the glass, brought round to the front, and secured to a tiny nail at the
edge of the niche; a snip--the thread withdrawn--and the clock would
start on the work it had been designed to perform. The only really odd
things about the whole affair were that the lowest third of the case was
filled with a liquid, thickish and emerald green and possessing a curious
iridescence, and that just beneath the niche was fixed a strip of ebony
tilted upwards and bearing in distinct opal lettering the word:

DANGEROUS

"Well, monsieur," said Christopher Craig, opening cheque-book, "I suppose
I can trust your clock to perform all that we bargained for. You will
give me your word for that?"

"Mr. Craik, I give you my word of honour that the clock will go for one
year and one day; that he will stop on the day appointed, within two
hours, on the one side or the other, of the hour he was to start at; that
he will make alarum forty-eight precise hours before he stop; that he
will strike only at noon and at midnight; and that, when the end arrive,
he will--"

"Thank you, monsieur."