door-key and then the latch-key. Both turned easily in their locks, the
door opened and the three men walked in.

A gas-jet was flaring in the hall.

"You see, governor..." said Gilbert.

"Yes, yes," said Lupin, in a low voice, "but it seems to me that the
light which I saw shining did not come from here..."

"Where did it come from then?"

"I can't say... Is this the drawing-room?"

"No," replied Gilbert, who was not afraid to speak pretty loudly, "no.
By way of precaution, he keeps everything on the first floor, in his
bedroom and in the two rooms on either side of it."

"And where is the staircase?"

"On the right, behind the curtain."

Lupin moved to the curtain and was drawing the hanging aside when,
suddenly, at four steps on the left, a door opened and a head appeared,
a pallid man's head, with terrified eyes.

"Help! Murder!" shouted the man.

And he rushed back into the room.