Inigo is being a good, obedient boy here and holding out his SCA. For a moment it does seem like he's about to take it off, but their words are enough for him to keep it on his wrist instead, waiting for the other to scan it, staring at the screen light coming out of.. his.. hand..?

Or light that's appearing as he's pointing, anyway. It's a little weird, especially to good old medieval boy over here, but he just lets it happen. It doesn't hurt, so he assumes that it can't be anything too bad.

"Ah.." He only now seems to realise something else, actually. "Having my system number might help you more as well. Two of the people that left the train came from the same world as me."

If they're trying to locate the people who disappeared from the train, then the more system numbers they have, the better, right? And it's not like they could scan people whose location is currently unknown in the first place..