"M-my name is R-R-R-Rabbit." The machine pony's voice is pleasant, warm and full of personality, his stuttering adding a touch of character.
The titanium pony shifts on it's hooves, making metal ring on stone. "I am The Spine." His voice is rich and dark, full of confidence with, perhaps, a subtly flirtatious air.
"They call me Hatchworth!" The bronze pony smiles brightly, much louder and more brash than his brethren. The pipe protruding from his hat releases steam with a whistle and he laughs cheerfully.
Twilight stands in awe of the mechanical colts, but when the one named Rabbit starts walking towards her with a jaunty step, joints whining, she watches him warily. He stops after a few hooffalls, rolling each joint and listening to it creak, mismatched photoreceptors darting up to look her over. "You'r'r're not Madame Celestia?" The other ponies seem to realize this as well, critical inorganic eyes fixating on her.
"I'm Princess Twilight Sparkle--" She tries to explain about Celstia's absence, but the peculiar pony cuts her off with a screech of gears.
"Another Princess! My lady," he bows his head to her, one hoof keeping his hat on his head, "it is an honor for a lowly automaton like myself to meet royalty! Spine, Hatchy, she's a princess!" The other two "automatons" mimic Rabbit, The Spine removing his hat and giving a deep bow, Hatchworth nearly planting his nose in the stone.
Twilight clears her throat awkwardly, not used to such enthusiastic praise. "Yes, well, I was Princess Celestia's pupil before I became a princess myself, but--"
"Ooh, a mechanic?" Hatchworth's high-pitched voice rings out over her, and he trots up noisily, The Spine following close behind. "My tank is low, and my left hoof is jammed, and my ears are sticking."
The Spine's rich voice takes over. "One of my spines is loose, and my tank is low on water as well."
Before Rabbit can fire off everything wrong with his internal mechanisms, Twilight raises her voice above the din. "I'm not a mechanic! I... Don't even know if I should be down here or not. I kind of just found the door while exploring, and I really don't know anything about any of this." The automatons seem disappointed. "But, I guess I can try? Show me what you need."
Rabbit swivels his head back and forth and seems to come to a revelation, his pupils dilating in surprise until blue and green take up each eye entirely. One hoof darts up to the brim of his hat to feel for something, but only meets the suede. "Where are-re-re m-m-my goggles?" A panicked look takes over his copper face, irises constricting into pinpricks once more. "I need my goggles! P-please tell me you know where my goggles are!?"
Twilight shakes her head. "I didn't see any, but I'm sure we can find them. Do you remember where you left them?"
The automaton pony gallops wildly over to a desk against the wall, yanking open every drawer and rummaging through the contents. "The P-Princess always gives me her goggles when she's not working on something! I always wear them! She wouldn't have, couldn't have taken them, oh please...." He starts taking things out of the drawers, throwing them every which way in a frenzy. "Th-the g-g-g-goggles are hers, but I get to wear them because I'm the oldest and I-- I just-- I don't know! Help!"
Before Twilight can say anything, The Spine approaches Rabbit slowly, his baritone voice gentle and understanding. "Hey, Rabbit, it's ok, the Princess probably just took the goggles with her. Look at this place, it's covered in dust. She hasn't been down here in a while. Maybe she's upstairs, working in the castle."
"Wha-what are you saying, Spine? That she l-left us down here?" Rabbit's eyes flicker, blue switching to green and green switching to blue, each eye shifting colors a few times with the sound of sparking fuses. "But she wouldn't do that! She'd never leave us here! Would she? N-No, no, no, no, no...." Rabbit slumps to the floor, covering his ears and shutting off his photoreceptors, a litany of "no"'s seemingly glitching his voice box.
"Rabbit, Rabbit..." The Spine sits down next to his brother, running a gentle hoof over his back strut. "The Princess is a busy pony, but I promise that she hasn't forgotten about us-- about you, ok? Why don't we go see the Princess? We can see the Princess, right?" He turns to Twilight.
Overwhelmed by the automaton's sudden meltdown, Twilight sputters a bit. "I, well, I'm not sure, I mean, I don't know if I was supposed to find this place, but... If it means so much to him, I can take you to see her. I'm sure she'll clear this up."
The Spine's eyes hold an awful lot of emotion for a machination when he looks from Twilight to Rabbit. "Do you hear that, Rabbit? The new Princess will take us to see Celestia. Do you want to go?"
Rabbit stands back up shakily with a little help, the "no"'s having faded away at the mention of seeing his creator. "Y-yes, please."