"Stupefy!"
A red flash streaked through the room hitting the old man inside. He crumples to the ground as a team of six men move in and surround his fallen form. A now adult Harry Potter tiptoes through the debris inside the dusty old loft. With a scowl on his face he walks towards the old man carefully observing every detail. The man wears clothes that seemed extremely outdated. This wasn't unheard of among wizards but this was different. These weren't wizard's robes. No these seemed like authentic French period clothes. 1700s maybe or perhaps 1600s, he wasn't quite sure. He would have to ask Hermione once he got back to London.
Harry takes a quick survey of the room, careful to look for any signs of spell work, magical runes or illusions of any kind. Once he's satisfied that there were none he steps over to the old man and with a flick of his wand removes the stunning spell.
Slowly the old man opens his eyes and begins lifting himself up. Before the man can get to his feet though, Harry pushes the man back down. He takes a knee and grabs the old man by the collar of his jacket and forces him to look into his eyes.
"Heinrich!" Harry says angrily. "Can you hear me? Where is girl?"
The old man begins to chuckle. It seems like a half choked coughing sound.
"Look at me dammit! Where is the girl you took tonight? Where is she? What did you do with her?"
The old man looks into his eyes again this time the smile stretching his wrinkled face into a horrid mask. His eyes suddenly flip inside their sockets and two bright blue eyes stare back at Harry. Harry recoils in horror, skittering across the floor away from the old man as two of the Aurors in the room move towards the old man and forcibly lift him to his feet. The old man's coughing increases until his whole body is shaking from it.
"Take him away" Harry barks at the two men. When they hesitate for a moment with concerned looks on their faces he shouts at them again.
The team of Aurors files out of the apartment and one by one disapparate.