"It’s not anything he did now, it’s what he did when..." She looked down, not sure whether telling Harry was a good idea. He already disliked Draco enough. She couldn’t tell Harry what Draco had done. Harry would kill him. And that wasn’t just a turn of phrase, either; Hermione was 99% certain that if Harry found out what Draco had done as a Death Eater, he would Avada him on the spot.