Terel is trying to build an electrical engineering textbook from his dozen or so conversations about electricity with Sadde so far. Wikipedia scans will help, probably? But not as much as actual electrical engineering experience would.

She can't really help with the experience part. The Wikipedia scans she can provide, though.

And then it's lunchtime.

"Sadde, yeah I'm calling her, um can you meet Sandy and I up at the library?"

"Absolutely!"

"Great, see you soon."

"See you, gorgeous." Click. Fly.

He's at the library listening to Sandy talk about what startup businesses tend to do. Which is mostly 'fail'.

Sandy is a short, dark-skinned woman with a very serious-looking face and hair in a tight bun.

And she is a tall-ish pale woman with an open face, short dark hair, and wings.

"Hello, love," she says, looking at Terel with utter and complete adoration, before turning to Sandy. "And you must be Sandy."

Sandy glances critically from Sadde to Terel and back. Terel looks slightly nervous, but it's kind of a default.

"Indeed I am," Sandy replies. "You must be Sadde the otherworlder."

"That would be me," she agrees, taking a seat by Terel.

"I'm reserving judgment on the half a dozen dozens of suspicious things about your situation on Terel's recommendation. And I suspect he hasn't told me everything yet. Which is fine, information has value, after all."

"It does. I'm not sure how much he told you and also not sure how much he'd rather I didn't so I'll take my cues from him."

"I'm mostly spacing it out so you don't implode or assume I'm insane."

"Yes," Sandy replies, "You of all people deserve the benefit of the doubt. Though I do want to see proof."

"Sadde, would you be fine showing off the key again? With appropriate cautions, of course."

"—probably not here in the library?"

"Yeah, no, same testing rooms from before."

"Lead the way, love."

Sandy makes a tiny bit of a face at the casual devotion on display... Something caught between disapproving and professional courtesy and confusion.

Terel leads the way as requested.

And when they get there, Sadde produces the key and demonstrates: an empty desert.

"Technically this is only proof of other worlds, not two and a half ages of scientific and technological advances, but it's a very big piece of evidence for them. I believe you two."

"Thanks for listening at all."

"The problem is that apparently the door only opens from the one side, and trying to open it from the other does not work. I'm sure there's somewhere in this world I could open that'd lead us back to mine but..."

"Large search space, and no qualifiers to help narrow it down." Sandy nods. "I wonder if there is Fair Folk magic that can track such a thing?"

"—now that would be truly something. I have no idea where this key even came from, as far as I know my world has no magical objects like that and yet there it was."

Sandy and Terel both shrug. "Probably want to close it if we're not going through."

She does, and locks it.

"If you really want your otherworldly products to be popular and widespread I believe you're going to have uses for an economist... But we can talk seriously about that once you have whatever knowledge base you need, and prototypes that I can twist into product ideas."