Enid's phone receives a notification. She thought she'd turned off most of those … oh, huh, someone saying hello in that Bluetooth mesh networking app nobody ever uses, no wonder she didn't turn off the notifications for it.
"Hi, who is this? Are you doing okay?"
The obvious reason for someone to be on an app like this is because their internet connection isn't working and their Bluetooth is, so it's likely they have some kind of problem.
"Hello! I am an alien with an unusual problem that only you-in-particular can help me with! I can verify this claim!"
If this is a prank, it's at least a neat one. Cool concept and it hasn't required her to go outside so far.
"What's the issue?"
"I am a member of the Committee for Contacts with Other Civilizations! We have been monitoring your planet for some time with the aim of helping it progress to transcend its current geopolitical struggles and join us among the stars; a colleague of mine has made substantial progress towards this venture but recently has run into major trouble. I need certain highly specific actions performed within the next two days in order to facilitate his extraction!"
That's more an attempt to talk Enid into doing things than an explanation of what, which isn't quite really what she was asking for.
"What actions? For that matter, what's your evidence?"
"Good point! Evidence! How much do you know about mathematics?"
"Some? More than the average person but I wouldn't say I'm a mathematician. I'm a bit surprised that you'd pick me without browsing my GitHub or my blog."
"That should be fine! Let's see, let's see... P ≠ NP? I suppose that isn't that interesting without the proof... how about a really big prime number that you haven't discovered yet?"
"I can claim that P ≠ NP without a proof too. :P Go ahead and try your numbers, though if they're too big I'm not going to be able to check them on my computer in a reasonable amount of time and you haven't really convinced me to pay for cloud computing on your behalf."
"Great!"
She sends the number.
Enid starts checking.
"This isn't going to be instantaneous, want to tell me more about anything while we wait?"
"Sure! Star Trek is terrible!"
"…I was expecting that you'd want to say more about your organization and its needs."
"Yes! The Prime Directive, very bad! Real situation -- exact opposite! Our organization seeks to uplift other human planetary cultures and their civilizations!"
"You know, the longer you go without saying what you need from me, the more I expect it to be an unreasonable request."
"How much do you know about fire suppression systems?"
"Not a ton."
"Okay. I have reason to believe that the fire sprinkler in the west stairwell on the third floor of your apartment building was installed incorrectly. This can be easily fixed by any individual but pattern analysis on building management service response times indicates it will not be fixed before the upcoming event if reported through normal channels."
Her computer is finished with things and she has now gotten the very unsurprising result. "You know, I don't think this number is prime at all."
"Ah. Yes. True. Honestly, I didn't think you were going to actually check. ^^;"
"I don't really see the point of entertaining you and not checking. So who is this really?"
"Oh, just someone who wanted to see if I could bluff you into setting off the fire sprinklers. Fair play though, you got me!"
"Bored, huh?"
"Testing!"
"Testing what?"
"If I'm good enough at bluffing! It's harder over text though..."