It's actually not that hard to see a changeling in disguise.
First of all, changelings are not as big as alicorns. It's not like they can suddenly just grow several inches, even shapeshifters have limitations.
Second, it's easy to spot a changeling up close since they all have fangs. Last time I checked, ponies did not have fangs.
Third, if someone panics (and by that someone, I meant me), then I – I mean, that someone – can simply throw a flash flare. A pony will yell "ARGH!!! WHY THE HAY DID YOU DO THAT?" A changeling will yell the exact same thing, but it's an easy way to prevent them from attacking.
Winding up the gearbox...
Also, more and more ponies have been trying to get in recently. It's like they are all starting to gravitate towards this room. I can't understand why, since I don't think books will resolve this war anytime soon. I been distracted several times already. And I am starting to run low on flares. (I need to stop panicking.)
Only a couple more days left. Then the teleporter will be recharged and I can finally go home. Just got to hold out for two more days.
That shouldn't be too hard, right?
The Mangle stopped for a moment to spectate on a current battle between some royal guards and some of the Gamma changelings. After a while, Lefty pulled down one of the drapes and flung it at a certain guard. The guard shouted out in surprise, and tripped over the drapes, causing him to crash head-first into another guard. The two guards tumbled down, barely missing a changeling. This caused the remaining guards to slowly back down as the changelings began to overtake them.
Righty snickered. "Don't you think you should save those trickshots for another time?"
Lefty shrugged. "I've got plenty of practice, I thought it was about time I put it to good use."
"Whatever," Righty rolled his eyes, but still grinning. "Anyways, should we get back to our task at hand?"
"Well, duh, we need Chrysalis to organize the hive again, let's go get that Elite Guard." The Mangle began to scurry along the ceiling again.
Navigating around the castle is a difficult feat to accomplish just by walking around. Even princesses have trouble locating certain rooms at a time of need. This is the main reason why a multitude of guards is always on duty, so that the amount of movement can be limited and easy to remember. Likewise, this was also why there are a multitude of changelings on this search mission. It becomes easier to search for a lost queen when there are a large number of ponies looking, so they can split up and continue the search without retracing steps. True, the more they split up, the easier they are to attack, but they have the darkness on their side. They know that they can hide in the shadows and follow the corridors until their mission is complete.
The Mangle simply takes this advantage one step further. Their so called "hook, line, sinker" strategy is exactly what it sounds like: they "hook" themselves to the ceiling, almost bypassing all security, then they move in a "line" to their desired destination, and they "sink" down to attack any unsuspecting creature. Their use of the strategy has been perfected to where almost no pony has caught them until it was too late.
Arriving at the Archives, Lefty took note of the surroundings.
"Hmm... are you sure that this is where Chrysalis is?" he asked.
"Of course it is!" replied Righty. "It's got to be. Isn't that the Elite Guard over there?"
"But that's the thing, he's just sitting there. I mean, that pony doesn't even look like an elite guard... He's panicking at the slightest sound, he keeps looking at that weird monitor. What if he was just a regular pony? You know how Chrysalis feels about hurting bystanders..."
"That's ridiculous, all the non-guards have been evacuated already, according to Scout. Besides, he has a guard helmet, therefore he is a guard."
"You know, I can't even see his face through the helmet."
"It's there, he's got the build of a guard pony."
"I honestly don't see anything"
"Well, look closer!"
"Hmm... oh, wait, I think I can- wait, what's he pulling out?"
*BRIGHT FLASH*
"ARGH!!! WHY THE HAY DID YOU DO THAT?" They shouted in unison. Rubbing their eyes, the Mangle tried to refocus on the character in the room.
"Is... is that... Big'ums?" Righty squinted his eyes. "It is! Nice job, Bigs, I didn't know you already took over this area."
"Uh..." Said Jeremy.
"Haha, still don't say much, eh? Well, that's fine. I should have recognized that flash anywhere, it was just you showing off your amazing changing stills, right?"
"...sure..."
Lefty began to take things seriously. "So, does that mean Chrysalis is not in this room then?"
"...no..."
"Do you have any idea where she is?"
"...ye- ...no..."
Lefty noticed that there was a hesitation, but simply disregarded it. "Alright, then, could you at least tell us what happened to the guard that was in here, a moment ago?"
"Uh... " However, before Jeremy got any further, a loud voice came out from near the door. "Soldier, are you in there? I need to talk with you."
Righty grinned. "Alright, Lefty, stop bugging Big'ums, he obviously knows what he's doing. We'll just go look for Chrysalis, you keep track of this room, capisce?
Jeremy nodded. And the Mangle quickly crawled through one of the hidden entrances. They were making such a ruckus that Jeremy did not notice the Captain of the Guards sneaking up on him.
"BOO!" yelled the Captain.
"AHH!"
*BRIGHT FLASH*
"ARGH!!! WHY THE HAY DID YOU DO THAT?"
"S-sorry, Captain, I mean Sir, I mean... uh..." stuttered Jeremy.
"Ah, it's fine" said the Captain, rubbing his eyes. "I'm used to it now, since you've done it to me several times. Anyways, I need to know if the changelings are close to finding Chrysalis."
"Uh... let me check... no, most of the changelings are still fighting the guards. Some more guards are needed in the east hallway.
"Good work, soldier, your technology has been of much use for us. Keep it up" The Captain walked away.
Well, I've only got two flares left, and there's still a day left before the teleporter is recharged.
Wind the box, wind the box...
I'm really running low on resources now, I can't keep this up very long. I'm going to have to find a stronger hiding place. Otherwise I will run the risk of-
...I heard a gasping noise. Strange, there's no one here. Unless some pony is-
Wait, there it is again... and again... Oh, It's coming from the cameras! Okay, so going through all of the cameras, I'll see
OH GOD WHAT IS THAT.
... actually it's not that scary. In fact, it's kind of adorable. It looks like... a giant pink ball of fluff. It's got so much fur on it, it looks like a pony could fit inside it. Maybe this is the changelings' plan for a trojan horse? Hide some changelings in a giant ball. It looks completely out of place, I wonder if
and it's gone. Where did it go? It's not in any of the cameras now.
Oh, that's because it's in my room...
Winding up the box...
"Um... hello?" I said.
"pffftftpfpfffttff" The really fluffy pony answered.