Because a disclaimer is apparently necessary, I own none of the characters mentioned here. This story is a tie-in to a part of the first Harry Potter book, by J.K. Rowling.
McGonagall
Harry stared at McGonagall
"This is important."
McGonagall looked absolutely dumbfounded:
"Something you have to say to Dumbledore is more important than the ministry of magic?"
Harry glanced at Ron and back to McGonagall and said:
"It's about the sorcerer's stone."
Calmly, she looked around the room, and dropped the stack of books she was carrying to the floor. As they fell to the ground, Hermione looked as though she was in terrible pain. She let out a tiny squeal of distress, and brought her hands to her face in horror. McGonagall looked up at the three, and frowned. She put her hand on her hip and spoke so softly that only she could hear.
"So be it." She said, her accent replaced with a thick russian one. Before any of the three could let out the blood-curdling scream she saw forming in their throats, McGonagall had already unholstered her M9 suppressed pistol and shot each in the forehead.
"My regards to Dumbledore."
McGonagall placed the weapon back in its place at her side, and took her wand in hand. She transfigured each body into a tiny spider, and promptly smashed each into the stone under her feet. She kneeled down in front of the remains, pointed her wand, and said:
"Incendio."
Whatever evidence, whether the blood on the books, the bullet casings at her foot, or the tiny, now dead, spiders at her feet; it was all in flames.