The carriage stopped at its destination, and Richelieu, getting out and taking a key from his pocket, opened the door of a house at the corner of the Rue de Richelieu.
"I must ask your pardon, mademoiselle," said the duke, offering his arm to Bathilde, "for leading you by badly-lighted staircases and passages; but I am anxious not to be recognized, should any one meet me here. We have not far to go."
Bathilde had counted about twenty steps, when the duke stopped, drew a second key from his pocket, and opened a door, then entered an antechamber, and lighted a candle at a lamp on the staircase.
"Once again I must ask pardon, mademoiselle," said the duke, "but you will soon understand why I chose to dispense with a servant here."
It mattered little to Bathilde whether the duke had a servant or not; she entered the antechamber without replying, and the duke locked the door behind her.
"Now follow me," said the duke; and he walked before the young girl, lighting her with the candle which he held in his hand. They crossed a dining-room and drawing-room, then entered a bedroom, where the duke stopped.
"Mademoiselle," said Richelieu, placing the candle on the chimney-piece, "I have your word that you will reveal nothing of what you are about to see."
"I have given you my promise, and I now renew it; I should be ungrateful indeed if I were to fail."
"Well, then, be the third in our secret, which is one of love; we put it under the safeguard of love."
And the Duc de Richelieu, sliding away a panel in the woodwork, discovered an opening in the wall, beyond which was the back of a closet, and he knocked softly three times. Presently they heard a key turn in the lock, then saw a light between the planks, then a low voice asked, "Is it you?" On the duke's replying in the affirmative, three of these planks were quietly detached, opening a means of communication from one room to the other, and the duke and Bathilde found themselves in the presence of Mademoiselle de Valois, who uttered a cry on seeing her lover accompanied by a woman.