From The Grey House:
The color drained from Natalia’s face. As far as she remembered, she never once mentioned her best friend to Zechariah or any Slayer. “Why did you bring her up?”
He gave her an awful grin as her hands were tied behind her. Natalia pulled against the men holding her to no avail. As she struggled, they wrestled her to the ground and tied her hands behind her back. She tried to scream, but a cloth was placed against her nose and mouth. She tried not to breathe, but it was useless. The chloroform seeped into her air passages and she passed out.