However, that's boring.
And they are like right next to an unclimbable mountain, which is not boring. And she never actually said she'd stay by the camp, they just assumed it. And she knows how to climb things! Safely, even! Nothing can go wrong with this plan. Up the mountain she goes.
Things that are less fun: falling into a massive sinkhole. That's not very fun. On the other hand, she lands on... a bed of flowers? A pile of enough bright golden flower petals, thick enough to completely break a fall of what must have been a hundred feet.
It's dark down here.
And there's something, large quantities of something. Energy. Raw power, floating around and filtering through itself and... creatures? And a shell of it, brighter than the sun, woven into a vast prison around what must be the whole mountain. It must have been hidden from the outside, imperceptible to groundsense, for anyone to have missed this for so long.
And there's something, its ground wrong in an intensely distressing and almost familiar way, moving through the earth toward her.
It bursts through the loamy soil. It's...
a flower. With a little face, one that somehow manages to be cute instead of plummeting into the Uncanny Valley. Its petals are glossy gold, just like the ones beneath her, but this one's seem almost to gleam with inner light.
"You're new to the Underground, aren't you? Goodness, you must be so-"
It stares at her, seemingly recognizing someone in her eyes. "Chara?"
"Well, you want to become strong, don't you? Everyone wants to become strong. But right now you're weak. Your soul's fragile and dull. I can help it to grow stronger by giving you some Love! Down here, Love is shared through these..." He waves a frond, and several glowing orbs appear around him. "Little white... 'friendliness pellets.'"
They float towards her soul lazily. "Try to catch them all!"
Sable has never been more tempted to ground-rip an arguably living being in all twelve years of her life.
But no matter how desperately suspicious the creature, she has no way of getting her apparently vitally important soul back without playing its horrible game.
So she braces herself and bonks the heart gently against a pellet.
The collision before felt bad.
This feels like a blunt, serrated, rusty knife being driven through her spine. She's left hanging on to life by her teeth and nails.
Flowey's adorable little face twists into a hideous grin. "You IDIOT. Did you really think someone would help you, down here? In this world it's kill or be killed."
In the distance, there's the sound of paws running towards her. Flowey looks to be too busy cackling to notice.
And the owner of the paws careens into the room.
She looks like something between a woman and a goat and a very sleek bear, and she is enormous. Sable's father standing next to her would look shorter than Sable herself looks standing next to him. And, incidentally, her paw-hand cups a magnesium-bright ball of fire.
The fire dissipates when she sees Sable. "I thought I heard-"
She stops in her tracks. Her eyes go distant. "Chara?"
"Who the blight is Chara?!" gasps Sable. She feels less like death now that the flower-thing's brilliant ground is being absorbed into her own, but this restorative comes with its own complications, namely an all-consuming agony as her damaged ground fails to reconcile with the foreign material.
"I-"
She shakes her head. "My adoptive daughter. She died. You look like her. Sorry."
She looks sharply at Sable's soul. "Who did this," she snarls, and makes a complex motion with her hands.
Energy suffuses Sable, mending her spiritual wounds and brightening her soul until it shines again. Her ground feels soothed.
"You're welcome," she says, returning to her usual clipped tones. "I healed you. It's not very difficult. 'What is happening' is a broad subject, but currently relevant is that you are the first human to fall here for multiple centuries, you obviously had no idea that monsters even existed, and that you look exactly like my deceased adoptive daughter, which is moderately distressing. In light of this I would like you to accompany me to my home so that I can protect you from harm."
"...Oh. You're new to this. It will follow you without collision if you don't concentrate on moving it."
She hefts Sable gently and places her on one of her massive shoulders. Reaching into a pocket, she pulls out some kind of candy wrapped in rice paper. "Have some candy. It tastes good and is generally soothing to traumatized children."
The candy tastes strongly unlike licorice.
The candy feels like being suffused with the same restorative light that the strange woman cast over her earlier. Threads of wholeness spread slowly through her ground. It feels good.
After a few seconds the candy melts and evaporates into nothing, but the wholeness stays. Its job is not yet done, but the work yet accomplished stands firm.
The woman sets off at a loping jog, apparently unaware of the miracle of medicine that has just taken place on her shoulder.
The woman strides past piles of leaves, marble pillars, and numerous very large frogs. One of the frogs tentatively croaks a greeting, which she summarily ignores.
"Tell me about this flower monster. It does not sound like something I know, which is troubling, because I know more or less everything."
"That is... profoundly impossible. There is exactly one other person alive currently who knew Chara, and he is not a flower. Although he would certainly try to kill you." She pauses. "Also, he has been known to call his bullets 'friendly pellets'. Hm."
She stops running and places Sable gently on the ground between two pillars. "Please stay here. I need to make a phone call, and possibly wring my ex-husband's miserable fluffy neck."
She pulls out a flip phone. "You can use it to communicate over long distances with other people who also have phones. You should take this one; it was Chara's, and she has no use for it anymore, because she is dead. You can use it to contact me if you become lonely or are in some form of physical danger. Press the following buttons to contact me."
She helpfully demonstrates the use of a phone.
The frog appears to be saying that many monsters will seem hostile toward her, but that for the most part, they are not bad people, they are only angry, or afraid, and that such a kind human should find it within herself to show them mercy.
"Ribbit, ribbit."
He adds that engaging one's foes in a conversation is often a good way to defuse such a situation. Compliments, in particular, rarely go amiss.
"How sure are you of that?" she asks sharply. "The world is full of people who thought they needed to do something awful for the greater good, only to find the greater good better served by a different intervention. You seem like a very nice frog and I'm sure you wouldn't be doing this if you didn't think it was important, but I won't accept that there's no other solution before I've even heard what the problem is."
It feels pretty substantial. But at a closer glance, it has a certain- softness, malleability. As if it was only half real, and the other half just a stratified nothingness. An admixture of material and magic.
She picks up the cracked halves of the bowl, holds them carefully together, and stares them down. They should stop being broken. They should, and if she has anything to say about it, they will. Her father does this sort of thing all the time - if she just -
Doing groundwork is still painful, but less so than usual, thanks to the candy. And now the bowl is in one piece again. She conscientiously refills it.
He attempts to convey these thoughts through interpretive dance, to severely limited effect.