threshold test

Murphy opened the door partway and peered out at me. The woman didn't look like the chief of Chicago PD's monster hunters. Her bright blue eyes were heavy, weary, and underscored with dark bags. She stood five feet nothing in her bare feet. Her golden hair was longer on top than in back, with bangs hanging down to her eyes. She wore a pale peach terry-cloth bathrobe that fell most of the way to her feet.
In her right hand she held her automatic, and a small crucifix dangled on a chain wrapped around her wrist. She looked at me.
"Heya, Murph," I said. I looked at the gun and the holy symbol and kept my voice calm. "Sorry to drop in on you this late. I need your help."
Murphy regarded me in silence for more than a minute. Then she said, "Wait here." She shut the door, returned a minute later, and opened it again, all the way. Then, gun still in hand, she stepped back from the doorway and faced me.
"Uh," I said, "Murph, are you all right?"
She nodded.
“Okay," I said. "Can I come in?"
"We'll know in a minute," Murphy said.
I got it then. Murphy wasn't going to ask me in. There are plenty of monsters running around in the dark that can't violate the threshold of a home if they aren't invited in. One of them had caught up to Murphy last year, nearly killing her, and it had been wearing my face when it did it. No wonder she didn't look exactly overjoyed to see me.
"Murph," I said, "relax. It's me. Hell's bells, there isn't anything that I can think of that would mimic me looking like this. Even demonic fiends from the nether regions of hell have some taste."
I stepped across her threshold. Something tugged at me as I did, an intangible, invisible energy. It slowed me down a little, and I had to make an effort to push through it. That's what a threshold is like. One like it surrounds every home, a field of energy that keeps out unwanted magical forces. Some places have more of a threshold than others. My apartment, for example, didn't have much of a threshold - it's a bachelor pad, and whatever domestic energy is responsible for such things doesn't seem to settle down as well in rental spaces and lone dwellings. Murphy's house had a heavy field surrounding it. It had a life of its own; it had history. It was a home, not just a place to live.
I crossed her threshold uninvited, and I left a lot of my power at the door as I did. I would have to really push to make even the simplest of spells work within. I stepped inside and spread my hands. "Do I pass inspection?"
Murphy didn't say anything. She crossed the room and put her gun back into its holster, setting it down on an end table.


Summer Knight Chapter 7, Page 91-92