As soon as Nancy's hand is close enough, Eponine goes to close her own fist over Nancy's wrist, so that she might pull the girl quickly into the shadows. It's not neat. It's not even particularly efficient, but style has gone completely out of the window in Eponine's desperate hunger.

Perhaps Nancy will notice the moon glinting from Eponine's fangs. Perhaps she's already realised Eponine's intention, before Eponine attempts to press her up against a wall.

"It won't hurt, Madame," Eponine mutters. "It is like a kiss. Just close your eyes and it will be like -" her face is close now.
"I swear, it won't hurt a thing."