[the mature speech and dress don't register as strange to him when he's been so disconnected from his peers in the first place — he himself seems to act beyond his berth, though not with as good a reasoning as the doctor]

[still, quirks in his world make all kinds of people behave in all kinds of ways, and he'd rather take the assistance at face value]

A more appropriate word is "tether". [pointedly... he's not a dog]

Do you have a belt on? If we link two, we can probably hook the end around that pole there. [a gesture to a thin column that stands in support at the entrance, and he looks to him expectantly]