The three of them had set their destination well, and appeared only a few meters away from the barrier. It was very intimidating from so close up, a dark dome constantly cracking with purple lightning all around its surface, the barrier itself expanding and contracting chaotically, like it was trying to expand and devour everything around it, the entire area around it completely devoid of life due to voracious magic needs of the dome sucking out all the energy from the earth.
"Dibs on breaking the barrier!" Sunset announced immediately.
Trixie looked at her "That will depend on what exactly is anchoring it, but considering your usual specialties, it's very likely you'd end up doing it anyway, Sunset."
"Just making my interest clear early, is all." Sunset answered.
Meanwhile, Twilight was making a small speech "For the sake of the stolen life of this land, I swear I will do everything I can to make this barrier be ended." She recited solemnly.
"First, let the Great and Powerful Trixie prepare our stealthy entry into the enemy territory." Trixie proclaimed, and went to work.
Sunset looked as Trixie started to fiddle with the barrier, knowing this would take a while. She turned to Twilight "Anything interesting to mention?"
"I've already thought of how to make our introductions when we actually meet other ponies in this first mission."
"But I thought Trixie would do the introductions?" Sunset tilted her head.
Twilight shaped the earth into two confortable chairs for her and Sunset to sit "She's going to introduce us when we meet enemies, but I convinced her to let me make the introductions to normal ponies."
The two of them kept talking, going back through their spell lists one last time to guarantee they knew exactly what the others could do. It wasn't really necessary, given they had already done so before coming, but you never knew when the inspiration for a new spell variation would strike. Sunset was particularly good at adapting under pressure.
Trixie didn't take that long to come back, now with a small ribbon on her mane. She showed two more ribbons to her partners "Here, put those in your manes. It should work to disguise our magic signatures enough that the barrier won't react. It will also make it harder for us to be caught by general magical detection."
"And Sombra will obviously have something much better than than general magical detection anywhere important, right?" Sunset said, as she was tying the ribbon to her own mane.
"He's still not ready for us." Twilight stated definitely.
The three of them walked up to the barrier, Sunset passed through without hesitation, Trixie held her hat in telekinesis as she went and Twilight took a deep breath before going through.
Inside the dome was like a whole other world. The sky was dark and full of even more of the purple lightning that could be seen fron the outside. What light could get through was weak and gray, as if passing through a heavy fog, and it was clear the envinronment suffered for it: There was no sign of any small animal or insect moving through the hills, the grass seemed to lack colors and the trees seemed to lack leaves.
Trixie took off her hat to an imaginary audience and said something about "starting the show", but Sunset wasn't able to understand it perfectly.
"Right," Twilight said "since I haven't felt anything like a magical alarm reacting, it seems that our ribbons worked perfectly." She turned to the other two "As planned, I'm going to gather information in the town" she indicated the town they could see in the distance "And then we decide on the next step."
The other two nodded, and Twilight's horn shined, then she took a step and seemed to stretch, before disappearing.
"Let's get to walking." Sunset said, starting the trot towards the town.
Twilight more or less understood why neither her partners nor her teacher understood when she explained how she did those kinds of things, but it still seemed so simple to her. Find a place to go, like that cloud, sense the light reflecting off her own body, redirect it to the destination, then change places with her own reflection. After all, the reflection was very similar to her.
Still, she was in her element as she moved from place to place, barely using any energy, while simply teleporting to the town would spend a lot of energy and cause enough ripples to allow a powerful mage to detect them even with the ribbons.
Finally, she reached the town, first standing on the side of a buiding (using an application of viewpoint manipulation so basic it barely warranted mention) then jumping to just under the earth, right in the middle of the town (by convincing the ground it was malleable enough to stretch).
Looking from underneath the earth, Twilight observed the town. It was easy to see that the ponies weren't happy. They kept to themselves and avoided making eye contact with each other. The streets were silent because there was no conversation, no peddling of wares and the ponies even seemed to try making the least possible amount of noise while walking. And of course, it seemed like they had been right about the fate of the guards. There were a few of them, here and there, moving robotically and with unfocused eyes. They were obviously brainwashed.
After observing for a while, Twilight noticed that one of the ponies on the street (a blue stallion with an orange mane and a lantern cutie mark) seemed to be slowly passing near every single other pony. Sensing that something was up, she swam towards that pony (having to hold her breath) and managed to catch him whispering:
"Tonight, at the Crafters home."
Bingo. It seemed like Twilight had found the resistance. She went around until she found a mailbox with 'Crafters' on it and managed to perceive the fact that the house that mailbox belonged to had a significantly large basement, probably the place where the meeting would be held.
She left the town and waited on the outskirts until her fellow disciples of Celestia arrived. She explained what she had found, and noticed that the day was getting close to ending.
"We should definitely meet up with the resistance. They should have information that would be very good to have." Sunset said.
"The night is cold here, so cloaked ponies will probably pass by unremarked. What about simply going to the meeting?" Trixie proposed, with a mischievous smile.
The other two agreed, and soon three cloaked unicorns were making their way through the streets, without attracting the least attention from the guards or other ponies (it helped that the ponies were deliberatedly staying away from each other). With a small spell to increase hearing range, they discovered the "password" that the members were giving to the mare who answered the door (long live the princess). And they were able to inflitrate the house and be led into the basement without any problems. Trixie was barely able to stop herself from giggling.
The basement was big enough for a large congregation of ponies, there was a small stage at the back, and the three of them took positions at the opposite end of the room from the stage. More and more ponies entered, to the point where it was becoming pretty full, but then a mare with a white coat and purple mane stepped onto the stage. The meeting started with simple reports of recent happenings, and Trixie waited to see when Twilight was planning to introduce them.
It turned out that she was only waiting for the right straight line. When the mare asked if anyone had anything extra to say, Twilight answered:
"I have something to declare!" said in a perfect stage voice, which immediately attracted the attention of everyone in the room.
Twilight's horn glowed, grabbing the concealing cloak in telekinesis, Trixie followed suit, and saw that Sunset did the same. Then, in perfect synchrony, the three of them threw their cloaks to the air (Sunset made them disappear, since they were only magical constructs).
"Under orders from Princess Celestia, we, her three apprentices, have come to free this land from the tyranny of Sombra!" Twilight continued, reinforcing her point with large gestures.
"Who... who are you?" The mare on stage managed to ask.
"I'm glad you asked that. Here!" She indicated Sunset by pointing with both forelegs to her side without actually turning "Is Sunset Shimmer. Among Celestia's three apprentices, she is the strongest!"
Sunset recognized the cue and gave a step forward before charging enough energy to make her whole body glow.
"Here!" She did the same thing, this time pointing to Trixie on her other side "Is Trixie Lulamoon. Among Celestia's three apprentices, she is the cleverest!"
Trixie knew it was time to show off. She reared up on her rear legs and cast an illusion spell strong enough to put images of Trixie and her name all around the room.
"And I!" Twilight indicated herself, rearing on her rear legs and tilting backwards "Am Twilight Sparkle. Among Celestia's three apprentices, I am the most mysterious." Her tone had become less boisterous on the last few words.
Twilight fell backwards, into a hole that appeared suddenly. Then she reappeared falling from the ceiling in a completely different part of the room, falling on another temporary hole. And that continued, with Twilight eventually falling sideways through the room before suddenly appearing back at her starting point.
"And we are here to help." She said, in a small but well projected voice.
Trixie approved completely of this introduction, but before she could say so, they were besieged by all kinds of questions and demands. It took a while for things to settle down, and the three had to do a lot to be recognized as truly being what they said they were, but eventually things calmed down enough for them to be able to actually talk with the leader of the resistance.
"My name is Ranger Time." She said "This group was formed to try and find out any weaknesses on Sombra's control of this region, and we have a lot of useful information." She looked downcast "We just haven't had any way of actually using it."
The three knight candidates were beside her on the stage "Just tell us and we'll do our best." Said Sunset.
Ranger smiled and nodded, before starting "First, Sombra never leaves the castle. He sends some kind of illusion that goes to inspect the town and the work camps, but we found out the thing had no smell and didn't leave any traces even when it should.
"Second, the castle is a leftover from an old noble that lived here. We have a map of it, and we updated it based on the testimony of the ponies who were sent there to work on renovations. We don't know what kind of magical defenses the castle has, but they are potent.
"Third, Sombra has access to 40 brainwashed guards who were sent here some time back, 17 pegasus, 14 earth ponies and 9 unicorns.
"Fourth, there are three work camps where Sombra forces us to work in order to produce for him. The first is the mine, where we harvest precious gems. It is supervised by one of Nightmare Moon's avatars, an unicorn who specializes in darkness magic. The second is the king's field, where he forces earth ponies to exhaust themselves growing food in those miserable conditions. We don't know what he uses it for. This place is supervised by the earth pony avatar, who seems to specialize in manipulating silver. The third place is the factory, where pegasi and unicorns are forced to charge jewels with their magic, before they are shipped to the castle. This place is supervised by the pegasus avatar, whose specialty is unknown, but her cutie mark seems to imply something related to lightning.
"Fifth, Nightmare Moon spends most of her time in the castle, but sometimes goes to the town or the work camps."
The mare finally stopped talking, and the three apprentices huddled up, discussing all sorts of possibilities and plans. Trixie was the expert in that kind of thing, but the other two weren't slouches either, and kept putting forth reasonable suggestions and ideas.
Eventually, they had the beginning of a plan, and turned back to Ranger Time.
"We have a plan." Trixie said "And if things go right, by this time tomorrow this entire region will be free."