She grins. "There are definitely spells for that, there are spells to make things cold, you just need to define the area they affect."

"...Ooh, if there's something to make areas hot too I can remove the need for fuel entirely. Even just permanent cold would make a nice passive gas-exchange engine."

"Gas-exchange engine? I'm sorry I don't know much about technology."

"Oh it's a - kind of engine that's different from most engines because it's very very efficient, and it can run off of less temperature difference than most other kinds, it's just kind of delicate and low power. Kind of niche. And wow is explaining what you can do to someone with no clue kind of hard!"

"It is alright. I'm fairly uneducated, but I have magic to compensate. I can piece together an explanation from books if I need to. What exactly would you need for the gas-exchange engine?"

"One object that is always colder, and one object that is always hotter, than each other. Big flat plates if possible. It would be nice to be able to turn them on or off but that's not really necessary."

"Do the plates need to be treated in some special way? Bar could supply regular plates. I could make rocks with different temperatures and that turn on and off if someone says a command word."

"Oh, plates means some kind of big metal disk not something you eat off of - I want lots of surface area. I can just buy those too. Rocks with different temperatures - could work, but that same thing in plates would be better, especially if the hot one is fire-hot. Could extract a couple kilowatts from it."

"Ah, metal plates producing or draining heat is totally doable."

"What kind of temperatures are we talking about? Nevermind, keep at the scrying runes for now and let me do some math, figure out how big a plate I want..."

Temperances focus on the scrying runes and after the estimated time has a sheet of cloth with a spell circle on, they can't roll it up, but they carry it sort of half folded to Walta's world.

Where she acts as doorstop and has Feume patrol around her. Still mostly in Bar so she gets translated, "Wild 'mon might come up to us, but Feume can handle them. This is a rest stop on one of the intercity routes, so probably no people."

Temperance nods, then she recites the verse of the spell and kills a bird (one caught from the backyard, not a mon). There is a weird wind that apparently erases the herbs out of the existence and then she stares vacantly at nothing for a minute.

Then she blinks disappointed. "Sorry, couldn't get anything, not even a confirmation that Entei is not real. Just a fuzzy fog."

"Hey! You speak English! I know a little English from my first world but not enough to actually understand what you said out there, come into Bar and repeat?"

Oh, right. She steps in and repeats herself.

Walta lets the door close for an impatiently waiting vampire of some kind. "Sorry for the inconvenience."

"That's disappointing, but it was totally worth a shot."

"Too bad it didn't work. Do you want try the other thing then?"

"I'm actually really sure it'll work if your magic does in fact keep the plates always the same temperature as described! Building an engine around them will take a while though."

"Sure. We can start on that now? Maybe with small plates," she holds her thumb and index finger a inch apart, "so I can see if we will need adjustments for the bigger version."

"Tiny plates are too small to even be worth trying, start with ones a foot across maybe. I really think you'll get bored and wander off if I build the whole thing right in front of you. Most people do."

"I can fly or swim around the backyard and Milliways is interesting. I suggested the tiny plates so I could adjust the spell which was originally meant for rocks."

"Aha.  Small plates, would it help if they're not like paper-flat? Slightly more rockish that way? I'm making a mental list to run to Bar for."

"Nah, if it works on metal it should work fine either way. It is just sensible to test smaller when you're trying spell variations."

"Alright. I'll be right back."

She is. And they head back to the room with a crate that the walker strains slightly under. This time she unfolds various boxes in the corner into a sort of workshop-ish area. and presses three-inch disks of aluminum out. "Here's the plates."

Temperance creates a ward and starts experimenting with the temporary versions of the spell, trying to get the temperature right first and the analyzing with a simple scry. She makes notes and ask Walta questions before coming up with variations. She can get a disk hot enough to evaporate or freeze water drops after a few minutes, and can probably improve on that.