While Mazeroux was executing his orders and M. Desmalions glancing at the fourth letter, the contents of which were unimportant and merely confirmed the previous ones, Don Luis took a pair of steps which the workmen had left in the corner, set it up in the middle of the room and climbed to the top, where, seated astride, he was able to reach the electric chandelier.

It consisted of a broad, circular band in brass, beneath which was a festoon of crystal pendants.  Inside were three lamps placed at the corners of a brass triangle concealing the wires.

He uncovered the wires and cut them.  Then be began to take the whole fitting to pieces.  To hasten matters, he asked for a hammer and broke up the plaster all round the clamps that held the chandelier in position.

“Lend me a hand, please,” he said to Mazeroux.

Mazeroux went up the steps; and between them they took hold of the chandelier and let it slide down the uprights.  The detectives caught it and placed it on the table with some difficulty, for it was much heavier than it looked.

On inspection, it proved to be surmounted by a cubical metal box, measuring about eight inches square, which box, being fastened inside the ceiling between the iron clamps, had obliged Don Luis to knock away the plaster that concealed it.

“What the devil’s this?” exclaimed M. Desmalions.

“Open it for yourself, Monsieur le Prefet:  there’s a lid to it,” said Perenna.

M. Desmalions raised the lid.  The box was filled with springs and wheels, a whole complicated and detailed mechanism resembling a piece of clockwork.

“By your leave, Monsieur le Prefet,” said Don Luis.

He took out one piece of machinery and discovered another beneath it, joined to the first by the gearing of two wheels; and the second was more like one of those automatic apparatuses which turn out printed slips.

Right at the bottom of the box, just where the box touched the ceiling, was a semicircular groove, and at the edge of it was a letter ready for delivery.

“The last of the five letters,” said Don Luis, “doubtless continuing the series of denunciations.  You will notice, Monsieur le Prefet, that the chandelier originally had a fourth lamp in the centre.  It was obviously removed when the chandelier was altered, so as to make room for the letters to pass.”

He continued his detailed explanations: 

“So the whole set of letters was placed here, at the bottom.  A clever piece of machinery, controlled by clockwork, took them one by one at the appointed time, pushed them to the edge of the groove concealed between the lamps and the pendants, and projected them into space.”

None of those standing around Don Luis spoke, and all of them seemed perhaps a little disappointed.  The whole thing was certainly very clever; but they had expected something better than a trick of springs and wheels, however surprising.