"The Iron Horse" Deleted Scene: The Nightmares · 3:56am Jun 4th, 2015
In the most recent chapter of "The Iron Horse: Everything's Better with Robots!" we see Twilight Sparkle wake up from a nightmare and fly outside to calm herself. She meets Gadget, who also confesses to having a nightmare. The two of them talk, they make up from their earlier fight, and they resolve to try harder to help Turing Test.
But this was not the original idea I had. Originally, I planned to show their nightmares and have Luna give them guidance. This got cut for a shorter, less distracting and less dark scene. However, in case any curious readers wanted to see it, I have here the original scenes. Consider it a peek inside the process and a small bonus for readers who want a little more. 
Enjoy!
Twilight's Nightmare
“Okay, just one more spell!” Twilight said excitedly. Turing was standing before her, her horn out and glowing, ready for the next spell. “Three teleports in quick succession! Ready… go!”
Turing flashed in and out of thin air once, twice, and then a third time at various points around the room. Each time she was in a slightly different position. In the last case, she reappeared balancing on the tip of her hoof on her left foreleg, a move worthy of a gymnast in the Equestria Games.
“Wonderful, wonderful!” Twilight laughed, clapping her hooves together. “Oh Turing, I’m so proud of you! You’ve mastered every spell I know and then some! You might be the most powerful magic user in all of Equestria now!”
“I believe that assessment to be correct.” She turned her attention to Twilight. “I have acquired what I came here for. You have now been rendered obsolete.”
Twilight didn’t understand what she meant at first, but then suddenly she was ensnared in a powerful magical aura. Turing had captured her and held her fast. She was unable to move, unable to even teleport to safety.
“Turing! What are you doing?!” she cried.
“My original mission was to acquire magical ability superior to that of other organic ponies. As one of the foremost magic users in the land, you were selected as my target.”
“But… but I thought we were friends!”
“You never believed such a foolish thing. I only feigned such a belief myself.” She approached Twilight and her violet eyes began to glow red. “I will replace you and soon all organic ponies will be replaced with machines like me. Your obsolete emotions and concepts such as friendship will be terminated. Immediately.”
(“Maybe she needs somethin’ from ya first and then when ya least expect it, she’ll walk right up and bam! You’d never see it comin’.”)
The memory of Applejack’s warning chilled Twilight to the bone. “Turing, please!” Terrified, she began to struggle against the magic which held her. But it was no use. Turing’s magic was too strong now. “Don’t do this…”
“Do not worry, Twilight Sparkle. I am not cruel. I have no emotions at all, in fact. I will perform my next function quickly.”
“Function?” And then her eyes went wide in horror as Turing wrapped a metal foreleg around her neck, ready to close like a vice and crush all that was beneath it.
With her strength, it would indeed be quick.
Gadget's Nightmare
Gadget was standing in a large, dark room. Or at least, it seemed like a room. But then she heard a sound in the darkness and looked up. “Hello? Is somepony there?”
She saw the source of the sound. Suspended from a rope, raised up high by some unseen crane, was Turing Test. She hung limply, the rope tied around her midsection. At Gadget’s voice, however, she turned her head to look down at her.
“Ah. Hello, Gadget Giroux. I see you have come to watch me be destroyed. That is very considerate of you.”
“Destroyed? What are you talking about?!” She looked and saw that now there was a huge metal vat just ahead of her. Turing was suspended directly over it. She could see a bright glow emitted from the top of it and could feel the intense heat coming from the vat. It must have been full of something unbelievably hot.
Molten metal. They’re going to melt her down!
She tried to run to stop whoever was doing this, but no matter how she ran, the crane and vat seemed no closer. She gave one last horrified scream as someone cut the rope and Turing swiftly dropped down into the vat. It was quick and she made no sound, save for a light plop as she dropped into its molten contents.
Frozen to the spot, her legs quaking in disbelief, she then watched as a small door at the bottom of the vat opened and a conveyor belt she’d never seen before carried out a solid gray block of metal. She knew what it used to be.
Crying out, she went over to it and threw herself over it. “Turing… I’m sorry… I couldn’t save you… I’m so so sorry…” She repeated that whispered apology again and again.
Then a familiar voice said, “Gad-get?”
She stumbled back, tripping over her own hind legs and falling backwards. The voice was slow and weak, but unmistakable.
“Hel-lo Gad-get,” the brick said. And then a pair of glowing violet eyes appeared (and somehow they managed to look sad, even pleading) and the voice continued: “Please tell me… Do I… make a… nice… brick?”
At this point, they'd both be brought out of their nightmares and the scene played out somewhat like it does in the final version.
This was cut for being just a little bit too dark and for not really contributing to what was already a dark chapter. Plus it brought in Luna a little too early and I have plans for her to make an appearance later. Her reaction to Turing, I'll leave that up to your imagination. 
See you next time!
That was a nice deleted scene. I can see why you left it out, but im glad you posted it here.
I see why it was cut but perhaps you should post the link to this earlier in the chapter where it is relevant with a warning.