He nods his thanks, with barely a pause in the (admittedly rather one-sided) conversation, and leads the way up the stairs.

It cannot be long until hài hour, can it? He will make sure Lan Zhan is settled comfortably and asleep before he goes back to his notes. Hopefully. Maybe.

He fully expects Lan Zhan to insist he stay in bed, though, and that might account for the slight dimming to his good cheer as he opens the door to his room.