The usual people and unusual talks

[Undyne]

When Sans's phone vibrated Undyne was about to turn away to gather her belongings, when a weird gut feeling prompted her to turn back. She peeked over his shoulder for just a split second, skipping to the bottom of the message - what with respecting his privacy and whatnot. It was the signature at the bottom she was interested in, and she recognized that.

"Gaster? THE Double-u Dee Gaster?"

Sans seemed to tense up for a moment. Or perhaps it was just her imagination. Could a skeleton even tense up, being made of bones and no muscles? "i doubt it's really him", he said dismissively as he put the phone away. "he had a more memorable way of writing." He stood up and dusted his shorts off. "i'm surprised that you know him."

"I don't. I read his name a few times, mostly in Alphys's lab. There's also some records in New Home's books, talking about him." She blinked as something resurfaced to her mind. Back from the fight against the tree. "Sans... there's something we didn't get to finish."

"what's that?"

"That big goat skull. Don't even try to play dumb, I know what I saw", she warned sharply.

Sans thought for a moment, then raised his hand. Besides him appeared the same thing she had seen him use in the fight, except that this one didn't have any bright light shining between its jaws. "you mean this?" It floated there for two seconds then disappeared into nothingness again.

"Exactly that. Explain to me why that skull looks the exact same as the machine that Gaster built. The Extractor of something, I believe it was called?"

"no, it was..." Sans briefly considered his words, then shook his head. "you saw it? when?"

"In the books. Alphys has... I mean, had a bunch of folders about a laboratory she told me has since collapsed or something. That Extractor thing was in them, there were blueprints and pictures of the finished product. Said that it had been invented by Gaster. And down to the pattern of bone on..." Not knowing the words, she dragged an index from the bridge of her nose towards her chin. "... on this line, your skull thing bears a striking resemblance. So I ask again, why do you have that skull that looks so similar?" To give her words more weight she leant closer to Sans, but the skeleton looked unimpressed.

"i've seen the extractor, obviously", he said. His straight answer startled Undyne, who took a moment to ask.

"When? And why did you copy the design?"

"hey now", said Sans with a slightly broader grin and a shoulder shrug. "this ain't detective conan."

"Sans..." She narrowed her eye.

"i guess i liked the design, that's all." When Undyne opened her mouth to follow up on this he raised a finger. "hey, i ain't lying. you know why not? ... because i'm a skeleton. you'd see right through me."

For the briefest of moments, Undyne made a grimace that uncannily resembled Frisk's expression, then she turned around and headed to the changing rooms. "You're going to turn me into that monster form one day, Sans. Out of sheer annoyance." Then she was off to the ladies' changing rooms.

Just as she was pulling her tanktop back on her phone buzzed and she hastily pulled it from her pocket. This had to be the Princess, or Alphys! Either way it was important...

The text she received

Alphys! But what was that about an acquaintance? Could it be...? She thought back to Sans's text, then stuffed her swimsuit into a pocket to desummon later and rushed out to meet the skeleton at the entrance to the springs area. Without taking the time to explain she grabbed the skeleton by his head, leapt over a pair of squealing monsters from the palace and rushed towards the exit while tucking Sans under her armpit like a log of wood.

Considering how she was rushing towards the exit without putting on her armor, Sans quickly put two and two together even without seeing Alphys's text. He just grinned as he enjoyed the type of fast ride that was normally reserved for Alphys when Undyne gave her a lift to the Waterfall dump area, or back to Hotland.