His visit to M. de Tréville being paid， D’Artagnan， quite thoughtful， took the longest way homewards.
Of what was D’Artagnan thinking， that he strayed thus from his path， gazing at the stars in the heavens， and sometimes sighing， sometimes smiling？
He was thinking of Madame Bonacieux. For an apprentice musketeer the young woman was almost an ideal of love. Pretty， mysterious， initiated into almost all the secrets of the court， which reflected such a charming gravity over her pleasing features， he suspected her of not being insensible to wooing， which is an irresistible charm for novices in love. Besides， D’Artagnan had delivered her from the hands of the demons who wished to search and maltreat her； and this important service had established between them one of those sentiments of gratitude which so easily take on a more tender character.
D’Artagnan， reflecting on his future loves， addressing himself to the beautiful night and smiling at the stars， went up the Rue Cherche-Midi， Chasse-Midi， as it was then called. As he found himself in the quarter in which Aramis lived， he took it into his head to pay his friend a visit， in order to explain to him why he had sent Planchet to him with a request that he would come instantly to the mouse-trap. Now if Aramis was at home when Planchet came to his abode， he had doubtless hastened to the Rue des Fossoyeurs， and finding nobody but his two companions there， perhaps they would not be able to conceive， any of them， what all this meant. This result required an explanation； at least， so D’Artagnan thought.
D’Artagnan had just passed the Rue Cassette， and already caught sight of the door of his friend’s house， shaded by a mass of sycamores and clematis， which formed a vast arch above it， when he perceived something like a shadow issuing from the Rue Servandoni. This something was enveloped in a cloak， and D’Artagnan at first believed it was a man； but by the smallness of the form， the hesitation of the gait， and the indecision of the step， he soon discovered that it was a woman. Further， this woman， as if not certain of the house she was seeking， lifted up her eyes to look around her， stopped， went a little back， and then returned again. D’Artagnan was perplexed.
The young woman continued to advance， for， in addition to the lightness of her step， which had betrayed her， she had just given a slight cough which betrayed a clear， sweet voice. D’Artagnan believed this cough to be a signal.
Nevertheless， whether this cough had been answered by an equivalent signal which had driven away the hesitation of the nocturnal seeker， or whether she had recognized that she had arrived at the end of her journey， she boldly drew near to Aramis’s shutter， and tapped at three equal intervals with her bent finger.
The three blows were scarcely struck when the inside casement was opened， and a light appeared through the panes of the shutter.
At the end of some seconds two sharp taps were heard on the inside. The young woman in the street replied by a single tap， and the shutter was opened a little way.
D’Artagnan then saw that the young woman took from her pocket a white object which she unfolded quickly， and which took the form of a handkerchief. She made her interlocutor look at the corner of this unfolded object.
This immediately recalled to D’Artagnan’s mind the handkerchief he had found at the feet of Madame Bonacieux， which had reminded him of the one he had dragged from under Aramis’s foot.
“What the devil could that handkerchief mean？”
Placed where he was， D’Artagnan could not see the face of Aramis. We say the face of Aramis， because the young man entertained no doubt that it was his friend who held this dialogue inside with the lady outside. Curiosity prevailed over prudence， and taking advantage of the preoccupation in which the sight of the handkerchief appeared to have plunged the two personages now on the scene， he stole from his hiding-place， and quick as lightning， but stepping with the utmost caution， he went and placed himself close to the angle of the wall， from which his eye could plunge into the interior of the apartment.
Upon gaining this advantage D’Artagnan came near uttering a cry of surprise. It was not Aramis who was conversing with the nocturnal visitor； it was a woman！ D’Artagnan， however， could only see enough to recognize the form of her vestments， not enough to distinguish her features.
At the same instant the woman of the apartment drew a second handkerchief from her pocket， and exchanged it for the one which had just been shown to her. Then some words were pronounced by the two women. At length the shutter was closed. The woman who was outside the window turned round， and passed within four steps of D’Artagnan， pulling down the hood of her cloak； but the precaution was too late. D’Artagnan had already recognized Madame Bonacieux.
It must be， then， for some very important affair； and what is the affair of the greatest importance to a pretty woman of twenty-five？ Love.
But was it on her own account or on account of another person that she exposed herself to such risks？ This was a question the young man asked himself， the demon of jealousy already gnawing at his heart， neither more nor less than at the heart of an accepted lover.
There was， besides， a very simple means of satisfying himself where Madame Bonacieux was going. This was to follow her. The means was so simple that D’Artagnan employed it quite naturally and instinctively.
But at the sight of the young man， who came out from the wall like a statue walking from its niche， and at the noise of the steps which she heard resound behind her， Madame Bonacieux uttered a little cry and fled.
D’Artagnan ran after her. It was not a very difficult thing for him to overtake a woman embarrassed with her cloak. He came up to her before she had traversed a third of the street. The unfortunate woman was exhausted， not by fatigue， but by terror； and when D’Artagnan placed his hand upon her shoulder， she sank upon one knee， crying in a choking voice，
