Then some words were spoken by the two women.

At length the shutter closed.
The woman who was outside the window turned round, and passed within four steps of d'Artagnan, pulling down the hood of her mantle; but the precaution was too late, d'Artagnan had already recognized Mme.
Bonacieux.
Mme.Bonacieux! The suspicion that it was she had crossed the mind of d'Artagnan when she drew the handkerchief from her pocket; but what probability was there that Mme.Bonacieux, who had sent for M.Laporte in order to be reconducted to the Louvre, should be running about the streets of Paris at half past eleven at night, at the risk of being abducted a second time?
This must be, then, an affair of importance; and what is the most important affair to a woman of twenty-five! Love.
But was it on her own account, or on account of another, that she exposed herself to such hazards?
This was a question the young man asked himself, whom the demon of jealousy already gnawed, being in heart neither more nor less than an accepted lover.
There was a very simple means of satisfying himself whither Mme.
Bonacieux was going; that was to follow her.

This method was so simple that d'Artagnan employed it quite naturally and instinctively.
But at the sight of the young man, who detached himself from the wall like a statue walking from its niche, and at the noise of the steps which she heard resound behind her, Mme.Bonacieux uttered a little cry and fled.
D'Artagnan ran after her.

It was not difficult for him to overtake a woman embarrassed with her cloak.

He came up with her before she had traversed a third of the street.