Rainbow stared blankly at the dot-covered window. "What is it?"
"Well, you know what SOS means, right?"
Rainbow Dash thought for a moment, then shrugged. "I think it's something you say when you're trapped somewhere and you need help... doesn't it stand for 'Save Our Ship'?"
"Well... it actually doesn't stand for anything. Ponies in history have just attached mnemonics to it so it would be easier to remember. It was originally just a three-letter code that a ship crew would use as a distress signal."
"Oh, OK." Rainbow feigned interest, nodding excitedly. "So, the pony who left this note. Does this mean they're trapped? Do you think we should try to find them?"
"Well, look at this next part." Twilight gestured to the pointillism message on the window. "Those are coordinates."
Rainbow slumped in her chair with a deadpan glare. "Great. More coordinates."
"Now, hold on a minute, Rainbow. 48.2ºN, and 67.3ºW. They're latitude and longitude coordinates. They indicate a point on the surface of the planet. That means we have a location," Twilight explained, walking to a globe on a table. She spun it around a bit, before proudly planting a hoof somewhere in the upper hemisphere. "There. That's where our mystery pony is."
Rainbow examined the globe. "Hey, that's not far from here! That's in Whitetail Wood!" Rainbow prepared to dart out the window.
"Wait! There's still something about this whole thing that seems a little off."
"Really? What is it?"
Twilight looked back at the globe. "This pony is supposedly trapped. If that's the case, then how in the wide world of Equestria did they manage to figure out their coordinates, let alone leave that message in the cave?"
"Huh."
Twilight wasn't expecting that answer. "Huh? What do you mean 'huh'? You've gotta admit it's a kinda strange."
"What? Oh, yeah, something's definitely fishy about this whole thing... Like, you're the only pony I can think of who would be able to figure out this code. It's like they meant for it to get to you specifically, not to mention the fact that I found it in the first place. How did they know anyone would even..." She trailed off with a quizzical gaze.
"Rainbow?"
"No, it's nothing! I'm not crazy!" Rainbow shouted abruptly.
Twilight was now utterly confused. "...What? I never said you were crazy..."
"Yeah, that's right."
"...Is there something you want to tell me?" The question elicited no response from the rainbow-maned pony. "Rainbow?"
"...No," Rainbow finally stated. Twilight knew Rainbow Dash was no element of honesty, but she had always been a horrible lier, and she was almost certain that Rainbow was hiding something from her. She decided not to press the issue, in light of their latest discovery and how excited she was to get going.
"Okay, Rainbow. Then what are we waiting for? To Whitetail Wood!" Twilight shouted, raising a hoof.
"Alrighty then, Whitetail it is."
"We're here."
"Where's 'here'?" Rainbow asked, glancing around at the snow-covered, leafless trees around them. They had been forced to stray from the path that twists and winds through Whitetail Wood in favor of getting to the coordinates. As they looked around, however, they were beginning to doubt the credibility of the curious distress call. There was nothing out of ordinary in sight.
"The coordinates they gave weren't very accurate, so whatever it is we're looking for could be anywhere in a 50 meter radius or so. Let's start searching," Twilight said. Rainbow prepared to fly off, but Twilight stopped her. "Don't fly. You might miss something."
Rainbow sighed. "Okay, fine."
After much searching, both ponies were adamant that they were on a wild goose chase.
"Twilight, I don't think there's anything here," Rainbow said, somewhat disheartened.
"I think you're right. Let's go back to the library," Twilight said, slowly turning around and put down a hoof to start walking. Her hoof hit something something solid, and with it came a dull, hollow thud. Twilight, out of sheer amazement at her luck, knocked on it a few more times just to convince herself it was really there. She frantically brushed away the snow and stale leaves to reveal a wooden trapdoor attached by hinges to a metal hull buried in the ground. "Rainbow? I think we've found what we came for."
"Twilight! What do you think is in there?"
Twilight smiled, a spark in her eyes. "DML."
The friends descended a short, metal stepladder. A cozy metal corridor extended away from the base of the ladder, ending about five feet away with a solid metal door. The odd thing about the door was that it looked like some sort of air-tight hatch, with a large, circular handle in the center. Twilight grabbed the handle and began to push. It didn't budge.
"Stand back, Twilight. Let me handle this," Rainbow commanded with an arrogant edge. She clutched the handle, bringing her legs up onto the door for support, and pulled as hard as she could. She flapped her wings for extra handle-turning power.
"Rainbow, You're turning it backwards," Twilight muttered with a dull expression.
"I knew that!" She tried turning it the other way, but it still didn't budge.
"Great. You probably got it stuck by tightening it too much." Twilight examined the handle. It didn't appear to be rusted shut, but it was hard to tell with the dim light. Then, she noticed a small, clear panel on the front of the handle in the center. Behind the window were three dials, each of which had an 'A' on them. Below each dial was a small, blue button. She tried pushing the first one. The first dial shifted until it displayed a 'B'. She tried to jostle the handle open again to no avail.
"Rainbow? I think this door has a password."
Rainbow groaned. "But how in the world are we supposed to figure out the password?!"
"Well, we could use brute force and try every combination. 26 letters in the alphabet, and three digits... that's 17,576 combinations! Let's get started!" Twilight said happily, returning to the dials.
"Twilight, no. This is ridiculous. It's take us weeks to figure this out!"
Twilight turned back to Rainbow. "Let me know if you have a better idea."
"OK! Point taken! Jeez."
It wasn't until the 73rd combination Twilight tried that she started to see how lost a cause it was. She slumped to the ground, exhausted. "I don't think we're gonna get this door open." She sighed.
Rainbow looked down at the ground. A few moments later she looked back at Twilight, a determined expression on her face. "No! We didn't come all this way for nothing! Come on, Twilight! What three-letter combination would this person use?"
Twilight thought for a moment, then her eyes lit up. "I get it! DML isn't a person, it's the combination for this door!" Twilight got up and pushed Rainbow out of the way and began buttoning in the combination. When she was done, she took a deep breath, then turned the handle. Something clicked, then the handle jammed. Twilight shook the handle back and forth, but it refused to turn any further.
"Hmm... we definitely got the combination right, so why won't it open?" Upon closer inspection, Twilight noticed a small keyhole below the buttons. "We need a key. I wonder what this place is, even. I mean, whoever owns it clearly doesn't want anyone getting in besides themselves."
"Maybe it's a spaceship!" Rainbow blurted childishly.
Twilight directed an unimpressed glare at her. "Yeah, Rainbow. Someone buried their spaceship in the middle of a forest, leaving all the trees unharmed, then wrote a cryptic message so we could find it and not even be able to get in."
"I gave you my answer. If you don't like it, then make your own," Rainbow said defiantly.
"Well... I have no idea what it is either, but it's getting dark, and I think a storm is coming. So, let's head back to the library, and we can come back and try again tomorrow, okay?"
"Sounds good," Rainbow said, darting up and out of the trapdoor. Twilight, having no wings, was forced to use the stepladder to get out. On her way up, however, she noticed some writing engraved into the edge of one of the steps. It read the following:
THE KEY'S HOLDER IS IN THE BLACK BOULDER
Taking note of the riddle, Twilight continued up the ladder. "Rainbow, meet me at the library tomorrow morning."
"Black boulder... black boulder... what could it mean?" Twilight knocked a hoof against her head, half cursing herself for not being able to figure out a simple riddle.
"Maybe it's the name of a place. Like, pull out a map and see if there's anywhere on it called Black Boulder," Rainbow suggested, reclining on one of the many cushioned chairs in the library.
"Hmm... good idea, Rainbow." She opened a drawer in the side of the coffee table to reveal a piece of rolled up parchment. She flattened it out on the table, and began searching for "Black Boulder". None of the names, however, were what they were looking for, until one rang a bell.
"Of course!"
"What is it, Twilight?" Rainbow got up to look at the map.
"Why didn't I think of it before? Dark Rock Cove! It's just off the coast near Sweet Apple Acres! I'll bet you anything that Dark Rock Cove is our mysterious 'Black Boulder'," Twilight said, tapping a spot on the map.
"Then what are we waiting for?"
"Well, this is it." They stood before a sandy beach. It was deceptively sunny, considering the temperature. The icy cold waves rolled in and broke just before slipping back into the deep blue ocean. Off the shore was a dark, weathered, cave-like structure that spanned a good two miles down the shoreline. Close to them, there was a parting in the rock, almost like an entrance to the palm tree forest behind it.
"Come on, Twilight! Race you to the jungle!" Rainbow darted away, leaving the bewildered lavender unicorn in the dust. She irritably swiped the sand off her face and started towards the "entrance" to Dark Rock Cove.
She arrived at the wide opening. The sand stopped somewhat abruptly and was replaced by grass as it continued towards the thick jungle. Twilight took a deep breath. She took a step forwards.
A loud thump resonated through the jungle, followed by a stifled cry.
Darkness.