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.