"This is assuming I can get Rosa here at all without going away from the door. Don't honestly know if I have cell phone reception where the other side is. I'll go check."

She doesn't have reception. "...Dammit."

"You might be able to get some kind of signal booster from the bar. She takes counterfeit and I have magic counterfeit powers."

"From the bartender? I haven't seen one."

"From the bar. She's a magical sapient bar." Pat pat.

"Ooh! I didn't even notice, sorry Bar."

It's quite all right. Can I interest you in a drink? First one's free.

"Sure, thanks. Something sweet and big, no alcohol. Clear heads needed today."

Juice!

It's good juice! "So I hear you might be able to sell a phone signal booster?" She reveals her phone, an old and simple thing. 2002 or something.

Yes, I can. How far do you need to boost signal?

"Thirty kilometers should do it. I know there's a train station at least that close, and I had signal there."

Bar produces an object.

She attempts to use it to make a call... Success! 

Rosa is wondering why she has to go to a middle of nowhere village, and shouldn't you be coming back by now, you said you'd killed the monster?

"Bella... Can I bribe Rosa and a driver with your counterfeit?"

"I have no idea if my currency'll be valuable in your world but I have some jewelry and stuff and Bar can do currency exchange, sure."

She talks some more. Rosa is eventually convinced to come out here with a combination of promises of money and insistence that she might be helping a lot of people. It'll take a few hours.

"Even if Rosa can recharge you, you still need to save the world, though. It just makes the end game not a vicious cycle."

"Yeah, I'm going to just park here till I have a complete solution. Rosa probably isn't even part of one but it'd be a useful demonstration in principle."

"...I. Hm. It's probably an unacceptably dangerous experiment to get you our kind of magic. I don't know if it would even be possible."

"What's involved?"

"You find a fade - a ghost that was a spirit bearer - who has a compatible personality and they give you magic. Or you make a deal with a genie or nature spirit and they give you magic and then hold you to the deal. Or you be evil enough that a monster forces magic on you without even asking because it thinks you'll do harm with it. The transformation itself is very, intense. And technically I am now a magical creature that happens to look and think a lot like a human."

"Eh, that's nothing, I'm technically this rock." She taps the back of her hand. "They don't even tell you that part up front, it's a surprise! But yeah, seems hard to coordinate a fade hunt without losing the door."

"Actually, Borbados, the mountain spirit, owes me a lot of favors. I might be able to convince him to activate you, if Rosa or someone else will hold the door for an hour."

"Ooh."

"Yeah. I'm just not sure if it'll interact badly, or if it's even possible, given that you're apparently a rock."

"Yeah, there's risk. Anything that might work has risk, probably. Are there, like, advance diagnostics that may help?"

"...If I call in a lot of favors, I might be able to get one question from this short-term precog up in New York."