Before they've fully adjusted to the darkness, and are aware via anything but the feel of earth under their hooves that the path has sloped downward a little, it has given way under them, some of the flora and some distressingly large rocks along with it. Clarity can't even teleport. It's too dark to see where she might be going.
Luckily for him, Brightblaze is second. She dives, gets herself under him - and finds out that dragons are heavy, even pony-sized ones, and she needs all four boots to achieve stable lift and get him safely to the ground. Which means not a hoof to spare to hang onto him, which means some very delicate balancing that's going to take time, which means she'd better hope Streak can take care of the three non-fliers by herself.
"I don't have time to explain," she says as rapidly as she can, "but if you let go exactly when I say, you will reach the ground safely. Trust me?"
"Good. Now," she says, and lets go and spreads her wings and leaps to catch Guiding Star just as she hurtles over the edge, while beneath them the tree swings its stately way over to catch Clarity at just the right place and time to take her weight and hold it. The leafy branches are quite comfortable, certainly in comparison to just about anything else she could have hit.
She takes the extra second to poke her head up above the cliff edge and look for any trace of Cordy in the path of the landslide.
No such trace exists where she can see - but she can tell the path splits halfway up, around a harder shelf of rock. Logically, therefore, Cherry Cordial must have gone the other way. If she had been flattened in any visible area, there would be signs.
Down goes Streak to extract Clarity from her tree.
"Yeah, at - some time - I have no idea how to tell what time given the little eternal night problem - we are all back together again in a part of the forest we haven't been yet."
"This information may not be as useful as it appears," says Streak. "One of those times when you look at the outcome before the plan is decided. I would have advocated for heading for the Elements as directly as we can; it seems Clarity would have advocated for finding Cordial first. Which choice would we have made?"
"I'm inclined to go ahead and follow your plan, since you'd be who I'd ask if I wanted to know how hard it would be to find her. The most obvious danger in the forest is wild animals and Cordial's better equipped to handle those alone than anybody else would be, and it could take hours if not days to find her."
The manticore is not rampaging; it's in pain. It is surprised by Guiding Star's approach - drops to three of its paws - and favors the fourth.
"Oh, you don't even want to eat anypony, do you?" says Guiding. "You're plenty good at finding food without ponies wandering in here. Okay - everypony close your eyes I have to do magic again -"
And she draws a thorn out of the manticore's paw.
The manticore licks her.
...toothier trees? That can't be right. But there it is, lit just slightly better than its surroundings - a tree with gnarled knots in the shape of malevolent eyes and its trunk split into a jagged gaping maw appropriately sized to swallow somepony whole, surrounded by spiky branches like reaching claws.
It creaks ominously.
It's Cordy. A dripping wet Cordy with twigs and leaves and fragments of bark tangled in her mane and tail.
"Hi, everypony," she says, and coughs again. "How have you been?"
Behind her, the tree slowly opens its mouth again.
"Fell into a pond," Cordy summarizes. "And when I got out, there were a bunch of these - " she jabs a rear hoof at the tree " - crowded around the edge, giving me the eye. I went around, and there were more behind them. It seemed like one way I could go was all scary all the time, and every other way there was a nice smell or decent lighting or something interesting dropped on the ground. So obviously something didn't want me going this way, and you have to figure the likeliest candidate for dark mysterious forces turning the forest against us is Nightmare Moon, who seems to be motivated to keep us apart. Therefore, scary path must lead to you guys." The tree creaks again. She gives it another kick. "I don't know why I held out hope that when I finally found you, the scary would stop."
And the tree's fangy maw and clawlike branches and knotty eyes untwist and smooth out into a perfectly ordinary tree.
The tree attempts to poke his eyes out. He cracks up as he ducks under the swing. The tree unscarifies on the spot.
After a while, Streak announces, "Agitated water ahead. A waterfall or a very unruly river." If the others listen closely, they might be able to hear the faint sounds that led her to this conclusion.
"Excuse me? Sir?" says Clarity. "Why are you crying?"
The serpent regains enough control of himself to reply. "Well, I don't know," he sniffles, "I was just sitting here, minding my own business, when this tacky little cloud of purple smoke just whisked past me and snapped my left fang clean in half, and now I'm positively unpresentable!" He opens his mouth to draw breath for more wailing, displaying a broken fang that does not match the one on the right.
She sits down on her hindquarters and takes off her front boots, then extracts several small tools from where they were previously hidden in the base of her mane. Soon she has detached the front plate from the right boot. With its sharp point and wide curved base, it's a nearly perfect match for the missing part of the broken fang, plus some overlap to get it firmly seated.
"There," she says, holding it up. "I'm just not sure how to get it attached. Any unicorns want to lend a hoof? Or a horn, more specifically?"
Clarity floats up the boot-part to the serpent's open mouth, and sticks it on. The serpent grins toothily at his reflection in the water, then beams. "Fabulous!" he proclaims. "Thank you ever so!"
The river is calming down as he stops heaving his coils around in dissipating distress.
She comes back to the non-castle side to deliver her final assessment. "Looks pretty solid, just a matter of hauling up the part that fell down and tying it nice and tight around those posts on the other side. Joy, wanna help?"
Clarity trots around the pedestal on which they're sitting. "There's only five, which - still means these are probably them, because the sixth one is supposed to be 'revealed' via a 'spark' when the five ones with known names are present. Can somepony bring them down for me? I should probably start trying things that might complete the set."
"Whoa - careful - they've lasted this long, but - okay," says Clarity, calming down when they've all safely reached the ground. She caaaarefully rolls them into a sort of ring shape and sits in the middle. She squints and starts the magical equivalent of feeling around in the dark.
When the tornado vanishes, she immediately takes to the air to see if she can spot any signs of where it might have gone.
Meanwhile, Clarity is coughing on the floor of the room, which is, as evidenced by the window-glow, brightly lit by ominous lightning. She blinks to clear the spots from her vision.
She gets to her feet, sees Nightmare Moon on the opposite side of the crumbling old room with the Elements in orbit around her - and -
has an idea, which will mostly only work if she can gallop a short distance without tripping, but maybe she can -
She breaks into a rapid gait, charging straight at Nightmare Moon.
"No - no!" exclaims Nightmare Moon -
and the spark dies down.
Why would the magical weapon that can supposedly defeat Nightmare Moon be several easily-shattered rocks?
Why didn't the spark work?
Why are they named that?
And, with more confidence than she feels, she addresses Nightmare Moon just as everypony else makes it into the room:
"You think you can destroy the Elements of Harmony just like that?"
(What if she can? Then all is lost, and the worst that happens is Clarity sounds kind of silly -)
"Well, you're wrong."
(Why are they called that?)
"The spirits of the Elements of Harmony are right here."
And, to Clarity's surprise almost as much as Nightmare Moon's -
the shards begin to float, aglow with subtle colors.
"Silver Streak," she says, "who proved trustworthy in a crisis, represents the element of Honesty."
A cluster of shards flow through the air in Streak's direction and orbit her.
Why are they called that?
"The spark ignited inside of me when I realized how glad I was not to be here alone - how glad I am to have friends beside me - how glad I am that they are my friends!"
There appears directly over Clarity's head an intact Element rock - stamped with the impression of a bell, just like her cutie mark.
"When those Elements are united," Clarity goes on, encouraged, "with the spark of friendship it creates the sixth Element: the element of -"
Hay, she has to name it.
"Magic!" she says dramatically.
The rock likes this name enough to glow brilliantly and inspire all of its rock friends to transform into assorted jewelry.
Clarity shuts her eyes against the bright glow of magic, smiling serenely.
A rainbow-colored fountain of power erupts from the Elemental accessories and showers down on Nightmare Moon, wrapping her up -
"I told you," winks Celestia, "to make some friends! I saw the signs of Nightmare Moon's return, and I knew that you had the magic inside you to defeat her - but there was no way you could have unleashed it without letting true friendship into your heart." She sighs. "Now. If only another will as well. Princess Luna."
Clarity sort of stands off at the margin of the festivities.
She's supposed to leave after the celebration, and has just remembered this fact.
"I, Princess Celestia," Princess Celestia says aloud as she writes, "hereby decree that the unicorn Clarity Bell shall be reassigned to take on a new mission for the land of Equestria: she will continue to study the magic of Friendship, and report to me on her findings from her new home - in Ponyville."
"I bluffed my way into activating the Elements of Harmony," says Clarity, floating the bell-festooned crown onto the nightstand next to the bed upstairs, "and we defeated Nightmare Moon with them, and now she's Princess Luna again, and I have been reassigned to stay here and continue investigating the magic of friendship."
"Yes. In the library, probably managing its... librariness... although I was hoping you might help me with that, since you know more about it than I do. At least whenever you aren't in school." Clarity produces a notebook and starts writing an outline of the events of the... night.