"Congratulations." Alecto beamed at Mandy. "Narcissa told me the good news. Of course, she also told me how Draco sullied himself, not once but twice, with half-blood mistresses. I'm certain we'll be able to cure him of that habit. You do understand." Her voice dropped low, confiding, "Narcissa was quite distraught. She does wish for a child of the proper lineage."
As if Narcissa were not lying there upon the ground, not feet from them. Draco's fingers tightened on his wand, unthinking as he brought it up to bear, the curse dredged from the depths of his mind. He had been forced to cast the Cruciatus curse when he was a teenager; this was the first time it came willingly, with all the force behind it of the anger over his mother's death, and his fear for Mandy's safety.
But Alecto was ready. Draco had forgotten how good she was, and it seemed that time in Azkaban hadn't destroyed her reflexes, his curse countered, and just as quickly returned, fire in his bones as he cried out and curled inward, unable to think.