Remember what I told you... [He was still speaking at Sirius's back.] About why I don't use my armor needlessly? I wanted to believe we could control the battlelust inherent in them, that we could shape our own destinies and... and that it was humans against evil spirits. Not other humans. When that reality faced me, I...

I threw it all away.

And because of me... because I couldn't bear to fight another human with that armor... my closest friends nearly died.

[He gripped Sirius's shirt, as if hoping he wouldn't turn around in that moment, and quickly said what was on his mind before his voice broke completely.] You didn't make Peter do any of those things; you weren't responsible for his actions. On the other hand, I'm- I'm responsible for mine.