d imperious
voice.

"In that case," he said, "be as quick as you can ... and do not stir
from your room...."

"But," said the girl, with a shudder, "am I to stay alone to-night?"

"Fear nothing. Should there be the least danger, the doctor and I will
come back. Do not open your door unless you hear three very light taps."

Jeanne at once rang for her maid. The doctor went to M. Darcieux, while
Lupin had some supper brought to him in the little dining-room.

"That's done," said the doctor, returning to him in twenty minutes'
time. "M. Darcieux did not raise any great difficulty. As a matter of
fact, he himself thinks it just as well that we should send Jeanne
away."

They then went downstairs together and left the house.

On reaching the lodge, Lupin called the keeper.

"You can shut the gate, my man. If M. Darcieux should want us, send for
us at once."

The clock of Maupertuis church struck ten. The sky was overcast with
black clouds, through which the moon broke at moments.

The two men walked on for sixty or seventy yards.

They were nearing the village, when Lupin gripped his companion by the
arm:

"Stop!"

"What on earth's the matter?" exclaimed the doctor.

"The matter is this," Lupin jerked out, "that, if my calculations turn
out right, if I have not misjudged the business from start to finish,
Mlle. Darcieux will be murdered before the night is out."

"Eh? What's that?" gasped the doctor, in dismay. "But then why did we
go?"

"With the precise object that the miscreant, who is watching all our
movements in the dark, may not postpone his crime and may perpetrate it,
not at the hour chosen by himself, but at the hour which I have decided
upon."

"Then we are returning to the manor-house?"

"Yes, of course we are, but separately."

"In that case, let us go at once."

"Listen to me, doctor," said Lupin, in a steady voice, "and let us
waste no time in useless words. Above all, we must defeat any attempt to
watch us. You will therefore go straight home and not come out again
until you are quite certain that you have not been followed. You will
then make for the walls of the property, keeping to the left, till you
come to the little door of the kitchen-garden. Here is the key. When the
church clock strikes eleven, open the door very gently and walk right up
to the terrace at the back of the house. The fifth window is badly
fastened. You have only to climb over the balcony. As soon as you are