Extend the Story - Add a Room

You draw your fists, ready for a brawl. You jump to the left, then to the right, throwing a couple quick jabs at the air.
Hm. hm. Now he knows you mean business.
You come in with a left hook aimed right at his rib cage! Before your fist can connect, he takes one step back. Whoosh, you've hit the air again.
Determined, you throw another attack! He steps back again. In short time you've about 38 strikes, each with malice and force. It's no use. He just keeps stepping back each time. Frustrated, you try for a tackle. He sidesteps, and you fall to the ground.

You turn around and, to your surprise, the lobby has stretched out into a narrow hallway.
The lobby springs back into place like a compressed slinky.

He tilts his head. "As I was saying, if you want to get in, you'll need to start by ringing the bell at the front desk."

Ask, "who are you?"