"Tsk tsk tsk... So impatient. Very well... I’ll spell it out for you. After you killed Weasley... well, it would have been a pity not to get rid of Potter too and also destroy the picture perfect image of the legendary Golden Trio by blaming everything on Granger and her husband." She shook her head and laughed. "Scandalous affairs, cold-blooded murders, that’s enough to shatter a fairytale to bits, don’t you think? Or rather, leave its body out to rot for everyone to see. Blowing something up can arouse empathy. But the sight and smell of a rotting corpse covered in flies? Turns most people away. Not me, but most people."