She considered him for a long time. His denial had taken some of the initial fire out of the impassioned rebuttal she expected to deliver. Lily didn't believe him exactly, his ability to wield Fiendfyre was more than just a subtle hint - it was dark, difficult magic. Regulus had known what he was doing.

In her normal life, the choice would be easy to make - but being here complicated matters. Willful ignorance was something she'd extended before under similar circumstances, and those had come to a terrible end. In the back of her mind, there were a lot of regrets about that particular friendship's very dismal end, and while Lily didn't address them directly (even on her own), they compelled her to keep talking.

"We agreed to watch each other's backs. I intend to continue to uphold that, what happened here more than demonstrates the merit of it." She tilted her head at him and held up a hand, gesturing that there was more to her thought.

"This time I could help, but I can't, I won't help you if it means you expect me to use magic like that." She would always throw a timely counter-curse, but if it came to casting those curses themselves, Lily didn't have it in her. "Do you accept this condition?"