"Extension charm on the entire ceiling, permanent sticking charms on the furniture, and the Anti-gravity mist filling the top half of the room, of course," Al explained to Dad as if explaining the alphabet. "If you jump high enough to get pulled into the mist, you reverse your up and your down and are able to use the furniture items." He eyed the ceilings once more, grinning. "I might try it without furniture first. Walking on the ceilings should be an interesting experience. It's a pity that the staircase and the doors would be unusable, but maybe it's for the best."