Cherry tapped at the ground with a metal hoof, raising and lowering it as she looked back at it. "It was part of a metal pony a unicorn made to explore the water. It broke, and I found it and made it into a dry swimmer. It helps me explore The Dry instead of helping dry ponies explore my home. That's fair, right?"

Celestia offered a little smile. "Very fitting." Her eyes darted to Twilight. "I trust you were involved with this?"

Twilight tensed a moment. "I smoothed things out with the pony in question, but it was entirely Cherry's efforts to enact the actual modifications. She really is a natural at mechanics." She walked around Cherry and pointed at her brightly-painted cutie mark. "It's her calling."

Luna gave a soft mmm as she rose to her hooves. "Living on land or in the sea, all ponies are bound by purpose. It is comforting in a way to see that even such distant relations are so similar in important ways."

"Excellently said." Celestia rose up to her own hooves. "Now let's see what kind of train we can get our hooves on."

Cherry's face split in a newly energized grin. "We can do it now?!"

Luna nodded towards Celestia. "As Sister implies, there is no better time than the present. This is something you clearly desire very strongly."

Celestia raised a hoof, showing off the metal-clad end of her limb. "There is one condition."

Cherry's ears spun backwards. Indigo stepped forward. "Don't be discouraged, Cherry. They seem super nice. I'm sure it's nothing."

Celestia nodded. "I hope it's nothing at all. We understand you two are just foals, exploring the world with wide eyes. We wish you both the best in your adventure, but I would like to speak to your leader. There are important matters to be discussed that would affect the future of both of our tribes."

Indie glanced between Cherry and Celestia. "Well, Cherry didn't even know we had one, so I guess it's up to me." He took a little breath before smiling. "I'll find them. Give me a letter and I'll get it to them." He looked back to Cherry. "I'll come back as soon as I'm done."

With a magical pop, Twilight appeared between Celestia and Indigo. With a nervous swallow, she rose to her full height. "I won't allow this."

Celestia raised a brow in silent question.

"They're friends, best friends. I won't let them be broken apart like this." She licked over her lips. "I... I'll find this Master of the Waves. You two, stay here. This is a royal affair and I'll take care of it."

Luna set a hoof on one of Twilight's shoulders. "That is very brave of you, but how do you propose to explore the ocean? You are very talented, but you are an alicorn, not a hippocampus, as our guests are."

Twilight gave a smile. "I planned to show this off later, but since we have one right here, I can use them as a template." She turned towards Cherry and Indigo, light sweeping from her horn over the both of them. "And..." With a bright sparkle of magic, she flopped to the floor, hindlegs gone, replaced with a new and powerful tail. She was sleek and ready for water. Twilight was a sea pony. "Spike, I expect you to keep the castle in order and keep an eye on our guests. You're the caretaker of the castle while I'm away."

Spike gave a salute. "I'll make sure nothing goes wrong. Good luck, Twilight."

Celestia bowed her head to Twilight. "This is no small task. Thank you, Twilight." Her horn began to glow as she hefted the aquatic Twilight into the air. "Please be careful. The ocean is full of peril and wonders you've never seen before. Err on the side of caution in your journey and return to us with good news." A smile spread. "Not that you've failed us in this regard before. I'm sure you'll be fine."

Spike hiked a thumb towards town. "You may want to bring some of the girls with you. Two heads are better than one." He snapped two fingers suddenly. "I bet Fluttershy would be perfect for this."

Twilight perked up. "Fantastic idea! Fluttershy would not only be a huge help, but she'd probably enjoy getting to meet so many new animals." She pointed towards Fluttershy's hut. "Onwards!"

Celestia began to trot off with Twilight held in her magic, bound for Fluttershy's cottage.

Luna nodded lightly. "While my sister is occupied, why don't we get to work? We promised to look into one train, did we not? Spike, will you be coming?"

Spike shook his head. "Twilight trusted me to watch the castle. I'll keep this place ship-shape for her. Go ahead and find that train."

Luna nodded towards him before turning to face the two sea ponies. "Very well. Shall we be off?" She led the way with certain steps towards the train station.

Cherry and Indie hurried to catch up with her, flanking her on the left and right. Cherry glanced in the direction Twilight had gone. "Is this really alright, for her to go and do this, for us?"

Luna raised an ear at Cherry. "This is hardly the first danger she has faced. We trust she will be safe in the end, with perhaps an important lesson on friendship in her hooves at the end of it."

Indie blinked softly. "I thought she's going to talk to the Master of Waves, not learn about friendship."

Luna snorted at that. "Everything is an excuse to learn about friendship around that pony. She is not the Princess of Friendship out of vanity. Her friend, Fluttershy, is truly a natural with wild beasts. She will keep Twilight safe from predators."

"I never got to meet her." Indie pouted a little. "When they come back, I would really like to meet this dry version of myself. I wonder which of my friends she'll run into..."

Cherry rolled her eyes. "Hopefully none of the hungry ones. It still amazes me how you can hang around such dangerous animals all the time without being the little bit scared by them."

"For a select few, it comes naturally to expose oneself to such hungry beasts of the land, and to not feel fear. For such ponies, there is no harm to be found among many dangerous animals." Luna tilted her head a little. "For most, however, it is specialized. I recall Fluttershy did make no attempt to befriend the hydra of the local swamp. Your own talents may not work so well on animals not born of the sea. An angry bear may be just as dangerous to you as any other pony."

"What's a bear?" Indigo frowned a little. "And a hydra? May I meet them?"

Luna gave a little smile. "You are brave. We can appreciate that quality. Fluttershy has a friend of a bear. Harry if we recall correctly. When she returns, surely she will gladly introduce you to him. That will be a safe way to test your empathy with the beasts of the land rather than to begin with something enraged or famished."

Cherry clopped alongside the new princess. "You're larger than Twilight, so you're more important, right?"

Luna paused a moment, blinking at that. She thought about the size of the princesses. Celestia was the largest. She and Cadance tied for second place, and Twilight was the smallest, though larger than many other mares. Size did seem to correlate somewhat to importance, even if they had never intended on it. "That is not how we determine significance. There are larger ponies in existence, with no title to speak of. Were I to gain or lose stature, my own title would remain the same."

"So are you less or more important?" Cherry tilted her head a little.

Luna gave a bemused smile. "My sister and I rule over Equestria together, so I suppose we could have a higher station than Princess Twilight, but we are peers. Here we are." She gestured at the train station, glad for the distraction. "We will ride to the central station and browse the locomotives they have retired. With luck, we'll find one that is not in too degraded a condition to be of use for your research and bring it back to Ponyville."

Cherry's expression brightened significantly as she stepped up onto the platform. "Do you think it'll run? We could ride it back here."

Indie answered quickly before Luna could, "That seems like a bad idea. What if we hit a train going the other way? Besides, they're not our tracks."

Cherry pouted a little at that. "I guess you're right... How will we get it back to Ponyville? Do trains work on the ground?"

Luna cocked a brow. "They do, but very very poorly. We do not recommend that. Neigh, we will hopefully find a small engine to claim and commission a team of ponies to transport it safely to Princess Twilight's castle." She didn't buy a ticket, and simply walked onto the train headed in the right direction.

When Cherry and Indigo moved to follow her, the conductor was less allowing. "Woah, hold your horses. Where's your ticket?"

"They are with me," spoke Luna with stern officiality. "Come, this way."

The conductor moved aside as the two stepped up onto the train. Cherry helped Indigo navigate the steps, hefting him up with a grunt to reach the smooth walkway inside.

With a soft lurch, the train began its rolling motion and they were on their way. Cherry and Indigo parked themselves by a window to watch The Dry rush past. They'd never been that particular way, and watching the exotic landscape scroll past was exciting enough to keep them entertained.

To say nothing of Cherry's musing of what sort of train she might secure. "Imagine if we find one that was just too old, but ran fine? That would be perfect! I could fix it up nice and good, take out one part at a time and replace it with a new one until I eventually had a brand new train!" She clopped her forehooves together from where she lay on her cushion. "I can't wait to see how all the parts inside work!"

"Such an effort would be more costly than effective for most," said Luna with a serious tone. "But you have the advantage of doing this for reasons of passions, rather than commercial. There are many places where one might miss one old part and risk a breakdown between stations if it fails. If I am told correctly, this is why trains are retired instead of rebuilt so often. We look forward to seeing the fruit of your labor."

Indie tilted his head. "One thing... How are you going to use it? You don't have tracks, and Luna said it won't work so good just on the ground."

Cherry opened a mouth to explain her great idea, only to realize she didn't have a great idea for this.

How was she going to use the train?

Author's Notes:

Twilight's off on an adventure! That we will probably not even glance at besides what she tells us when she gets back.

Meanwhile, Cherry and Indie are off with Luna to fetch a train! What typo awaits them to get in the way of securing a locomotive?