Harry had noticed the man staring at him, not exactly a new thing for the poor man who stood there looking back at the stranger. He was used to getting recognized as the "Boy Who Lived", but the name that came out of the metal man's mouth was different. And Harry looked a little confused.
"No. It's Harry, Sir. Harry Potter. I'm an auror with the Ministry of Magic." He stepped forward a bit, his wand now at his side, hoping that greeting the man might help break the tension.
"There's no need to be alarmed- these uh, the Doctors are just trying to help. You're in Cardiff, Wales. 1999. We're not really sure what's going on, but the Ministry sent my friend Ron and I to help explain the situation."
Thirteen, meanwhile, watched Eleven for a moment, waiting to see how the not-cyberman would respond, but hoping for the best. Probably best to let Harry take it from here.