As Trixie trotted through the tunnel, we could see it branched off into many smaller passages, each one going beyond the reach of our lights. Beside that, I noticed her magic never let go of me for a moment.
I got curious about that. "Mom, what's up with the magic?" Sure, I remembered my real mother, but I felt something for Trixie. She was my pony mom, if that made any sense. In a perfect world, I'd introduce them to each other, and invite Trixie over for thanksgiving. She probably wouldn't like the turkey overly much, but mom's stuffing...
"Familiar?" She was staring at me. Did I space out. "There you are. Trixie said she didn't want us being separated again. The shadow loves pulling you away from Trixie, and she won't tolerate it any further."
That made a kind of sense. "But you can't hold me all day and night. If it wants to get us apart, it'll wait for the right time. I don't think that's the last we've seen of it."
She tossed her mane with a soft hmmph. "Then Trixie will have to banish it properly. Perhaps to Hades. I hear that's an ideal place for ne'erdowells."
Could ponies do that? She laughed at my expression. "Did Trixie not mention how Great and Powerful she was?"
I gave her neck a soft pet and she snorted. "Why do you keep doing that? Trixie is not your pet. Attempt to withhold your overwhelming desire to stroke her magnificent coat."
Her neck happened to be a handy place to hold as she walked, and was soft beside. Still, boundaries. I kept my hands still and leaned over her a little, trying to peer into the dark. "Pinkie could have gone into any of these tunnels. Which one do you think we should try?"
She tapped her chin a moment. "They all look the same to her. All things being equal, it matters little we select." She turned and started for one of the tunnels. as she turned her horn for the wall and it sparkled as a stencil of herself appeared doing a victorious hoof's up. "There. We will know which we have explored."
A form of smoke seeped from the wall ahead of us, quickly forming into one of the shadow ponies. It glared at us but didn't immediately spring to attack. "You took one of ours. We took one of yours."
From the darkness, the form of Sweet Tooth was hurled, still half tarry monster, half softly sniffing pony.
"Go."
Trixie raised a hoof, ready to argue, but I had a different idea. "Alright. We'll meet again."
The shadow laughed, a dry and distant sound. "So easily you concede. Do you like her so little? I will enjoy the look of pain on her face."
I shook my head. "Tell her I know she'll be alright, and that I trust her."
"More the fool be you!" The shadow turned as it faded away, vanishing into the wall.
Sweet Tooth looked up at us a moment before she slowly rolled up. "H-hello again... I'm sorry... I've cost another pony their lives."
Trixie softly snorted. "Trixie does not trust Pinkie for many things, but surviving she can do well."
I gave a quick nod as I tried to slip off of Trixie, but her magic held me tight. "Sweet, do you know how long you've been down here?"
Sweet's tarry ears flicked back as she ran her normal tongue over her black snout. "I'm not sure... Nothing is where it should be. Please, you've been so kind to me, tell me what's going on?"
Trixie turned around slowly. "Come with us, Sweet Tooth. Trixie will show you the way out."
"Out?" She rose to her hooves and started following. "Out of where?"
"Did you ever hear of outer space?" I wasn't sure any but a few of them had, from what I had seen.
She shook her head with blinking eyes of tar. "Isn't that just a made up place? How can we go there? It's not safe!"
Trixie looked over her shoulder. "We made it through there, and we're fine, are we not? Have faith in Trixie and her astounding familiar. We won't lead you astray."
"Y-yes, of course..." She reached up with a hoof to her own face. "What happened to me?"
I took a slow breath as I readied to answer that as best as I could. "Well, you were in an accident. A lot of ponies were. Your old city is gone. We'd like to bring you to our city."
She was silent for a time, clopping along with her head low. "So... he's gone. I'm a terrible mother."
"No! I mean, there wasn't anything you could do about it. Beating yourself up isn't going to fix things."
She gave the ghost of a smile. "And pretending it's alright won't bring him back, either."
Trixie swiveled an ear back at Sweet. "Did you have a husband?"
"No." She pawed at her head again as she walked. "Why am I so hideous? Why didn't you just destroy me when you had the chance?"
I tried to pull away, but Trixie's magic was quite adamant. "Trixie, let me up. I'm not going far, I swear."
Trixie looked over her shoulder as she walked forward. "She doesn't mean to cast doubts, but it hasn't worked out well so far."
Sweet moved up beside Trixie and set a hoof on her shoulder. "Even if he's not here... you have to let them go, or they'll resent you."
Shrinking back from the touch, Trixie huffed. "He is not my foal!" She stopped and lowered to the ground. "Fine, but stay close to Trixie, alright?"
I slid off of her back and moved around to Sweet Tooth. "I don't think you became... this... to hurt people."
"I didn't?" She tilted her head at me. "All I knew was hunger. How's that a good thing? How could that possibly be anything but terrible? I'm still hungry." She put a hoof to her furry belly, rubbing gently. "You're not even safe around me."
I reached for the hoof on her belly and squeezed it as my other hand slowly pet over her tummy. "Think back. When was the last time you saw your, uh, foal?"
She smiled even as new tears began to build in her black eyes. "Little Tummy Rumble... He loved having his belly rubbed, just like that. I remember trying to do something. I was..." She trailed off with a deep scowl. "I can't remember. He was there. I was there. Why didn't I save him? Why am I still here?"
Trixie turned to us. "Trixie sees where her familiar is going. If you can only remember engulfing things, did you try to do this for your child?"
Her eyes widened. Sweet shook her head violently. "I didn't! Oh please tell me I didn't eat him!" She collapsed to the ground, weeping like a broken siren.
That wasn't what I had meant to work towards. "No no! Shhh. You did what any mother could."
"W-what's that?" She looked up, her muzzle running with goopy lines. Every word made them stretch and wobble.
"You threw yourself around him, to protect him. If you could just get him to safety, you thought. If you could take the horror for him. You wanted to hug him so tight you'd be hurt instead of him."
She slowly sat up, nodding even as she shuddered with a silent sniffle. "But it didn't work. Where is he? Why am I still here?"
Trixie reached out and poked Sweet Tooth in the side, where her furry and goopy halves met. "You ejected Trixie when you wanted to. Is he still there, she wonders?"
Sweet went rigid. "Could it?" Her runny ears raised up. "But it's been so long..."
I hugged her, even if that meant part of me started to sink into her. "We're here for you. When you're stronger, and ready, we'll get him back."
She quickly pushed me back with a hoof. "I don't want to eat you, kind, uh, what are you?"
"He is my familiar." Trixie smiled proudly. "He is a human."
"Human, yes. Thank you. Thank you so much." She raised a leg and wiped off her face. "I can handle this. If there's some chance, even a little one, that I can get him back. I'll hang in there."
"Frisk," I corrected, but was that my name before? That didn't want to come to me yet. On one hand, I wanted to hurry it along, but the rest was coming at its own pace. I'd learn about myself as I learned more about these dark ponies and their past. "My name's Frisk. Nice to meet you, Sweet Tooth."
She offered a hoof with a smile. "You saved me, all of you. Thank you." We shook gently as she continued, "We'll find your friend, the pink one. They said I wasn't 'one of them' anymore, and threw me out while dragging her away. It was terrible! What are they?"
Trixie gestured towards the tunnel we had come out of. "Umbrum. Quite a menace to the ponies of the Crystal Empire."
Sweet Tooth had no idea what that was, but we put the question aside for the moment. We had to get out of these tunnels! At least the river gave us a clear path to the city. I kept half an eye on it as we walked. "If it wasn't for that waterfall, and all the sharp rocks, I'd say we could just float down to the city and save a lot of time."
"Would that it were so simple, familiar." Trixie frowned. "Wait, Trixie has a sudden idea. It's crazy, but she thinks it may work." Before either of us could question it, she took a deep breath and bellowed, "Aquator, you sunken example of shadow, come before Trixie!"
The water before us began to froth violently before the familiar shape of water and darkness emerged, forming into the horse-sized pony. "Are you that eager to be crushed early, witch?" His eyes, mere impressions of focus without actual pupils, seemed to turn to Sweet Tooth. "You've taken a hostage?"
Sweet recoiled. "What? No! They're my friends." She took a slow step forward. "W-who are you?"
"I am Aquator, harbinger of the dark and crusher of the light. You would do well to avoid these champions of the light."
Trixie scoffed lightly. "She is in our care, and will be handled well, we assure. We survived your little 'challenge', and defeated the second root of your power. Take us to the surface so that we can move to the next."
"Why should I?!" He stomped a hoof to the ground as he stepped free of the water. "You should rot forever in the dark, lost and alone."
I spread my hands wide. "You won't have your proper victory until we fail against your forces and then, ultimately, you. Besides, we're not lost, or alone. The river says which way to go, and we have each other, and Sweet Tooth."
He frowned, water rolling over water in his scowl. "Your logic infuriates me. Let us hasten your defeat then." He stepped back into the water, but his back remained above the surface. "Get on, and hold tightly, for I will not slow for you. Should you fall, that will be your own failing."