The fire's been stoked recently, Charlie will notice, because the warmth inside hits him like a blanket to the face and the warm glow is disparate for this time of night.

The reason is obvious immediately, at least: a small pile of laundry is hunkered in front of it, ostensibly reading but for the fact the book in its lap is closed, and at the sound of the door Arthur's attention snaps up - but there's no hostility to it. Instead Charlie will see a rapid progression of confusion-surprise-relief-anxiety, and Arthur swallows thickly before he manages a nervous smile.