Still more, the light which had shone for an instant disappeared, and all was again in obscurity.
D'Artagnan thought this could not last long, and continued to look with all his eyes and listen with all his ears.
He was right; at the end of some seconds two sharp taps were heard inside.

The young woman in the street replied by a single tap, and the shutter was opened a little way.
It may be judged whether d'Artagnan looked or listened with avidity.
Unfortunately the light had been removed into another chamber; but the eyes of the young man were accustomed to the night.

Besides, the eyes of the Gascons have, as it is asserted, like those of cats, the faculty of seeing in the dark.
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 observe the corner of this unfolded object.
This immediately recalled to d'Artagnan's mind the handkerchief which he had found at the feet of Mme.Bonacieux, which had reminded him of that which he had dragged from under the feet of Aramis.
"What the devil could that handkerchief signify ?" Placed where he was, d'Artagnan could not perceive the face of Aramis.
We say Aramis, because the young man entertained no doubt that it was his friend who held this dialogue from the interior with the lady of the exterior.

Curiosity prevailed over prudence; and profiting by the preoccupation into 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 utmost caution, he ran and placed himself close to the angle of the wall, from which his eye could pierce the interior of Aramis's room.
Upon gaining this advantage d'Artagnan was 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 inside drew a second handkerchief from her pocket, and exchanged it for that which had just been shown to her.