Harry and Jayne
Jayne had never felt such a shock as the sight before her, her own hand shoving something - she finally identified it as a letter opener - into the young man's throat. Not just any young man, but Harry Potter.
What have you done!
"What I said I'd do - get my memory back. See?"
Before her eyes, the whisp of dark, cloudy smoke danced away from Potter's body, and into the tiny box still clasped in her hand.
But- but you killed him!!! You didn't say you'd kill him!
"Honestly, what did you think I would do?"
Anything but kill him. Why? I'm not a killer.
"Oh, but child... I am. And in your body, so are you. That's what they'll think, if they catch us. Now, unless you want that to happen, shut up and let me work."
The letter opener was withdrawn from the body - Potter's body - and secreted into a pocket in Jayne's robes. She couldn't feel it once it was enveloped in the cloth - that was why she hadn't noticed it there. It must have been spelled somehow. She watched impotently through her own eyes as a scourgify was cast to remove any accidental blood spatters, then with a glance up and down the hall, she made an escape into the main room.
But instead of leaving as she'd thought, she was taken to the bar for a drink.
"Leaving would be suspicious. It's all right, I dropped your wand off at security earlier. All the bases are covered, darling."
In horror, Jayne simply retreated further into her own mind and did as commanded.