He Was Laughing

"I- I will never forget it. I still dream about it sometimes. A crater in the middle of the street, so deep it had cracked the sewer below. Bodies everywhere. Muggles screaming. And Black standing there laughing, with what was left of Pettigrew in front of him..." Sirius was never quite the same after his duel with Peter. Whether he went mad from it or Azkaban, no one knows.