ThETA

From UBIK by Philip K. Dick :
....The door refused to open. It said, “Five cents, please.”
He searched his pockets. No more coins; nothing.
“I’ll pay you tomorrow,” he told the door.
Again he tried the knob. Again it remained locked tight. “What I pay you,” he informed it, “is in the nature of a gratuity; I don’t have to pay you.”
“I think otherwise,” the door said. “Look in the purchase contract you signed when you bought this conapt.” In his desk drawer he found the contract; since signing it he had found it necessary to refer to the document many times. Sure enough; payment to his door for opening and shutting constituted a mandatory fee. Not a tip.
“You discover I’m right,” the door said. It sounded smug.
From the drawer beside the sink Joe Chip got a stainless steel knife; with it he began systematically to unscrew the bolt assembly of his apt’s money-gulping door.
“I’ll sue you,” the door said as the first screw fell out.
Joe Chip said, “I’ve never been sued by a door.
But I guess I can live through it.”
A knock sounded on the door. “Hey, Joe, baby, it’s me, G. G. Ashwood. And I’ve got her right here with me. Open up.”
“Put a nickel in the slot for me,” Joe said.
“The mechanism seems to be jammed on my side.”
A coin rattled down into the works of the door; it swung
open and there stood G. G. Ashwood.....