The three mares flew to the Wonderbolt Academy. While Sunset enchanted her hooves to be able to walk on clouds, Rainbow Dash watched the airstrip, remembering her stay that led her to becoming a Wonderbolt reservist. Behind the academy's administrative district was a restricted area. They arrived in front of a hangar that was guarded by a pegasus officer wearing an indigo blue shirt and cap. His gaze hidden behind tinted sunglasses, he greeted them as Spitfire guided them inside.

Spitfire sighed as she walked down an all-white corridor. "First of all, I want you to know that I was briefed yesterday afternoon by Princess Luna on the status of Princess Celestia. Therefore, in accordance with the letter, I am initiating what she called the project..." She stopped, sighed again, rolling her eyes before casting a reproving glance back. “... ‘Like Every Wonderful Day.’ No comments, you two," she ordered curtly.

It took two seconds for Sunset to understand and need to hide her laughing lips behind a hoof. Rainbow needed Sunset to share the secret hiding in the acronym to understand why Spitfire reacted the way she did. The ensuing uncontrollable laughter echoed in the hallway.

The leader of the Wonderbolts used a wing to hide her face, the contagious laughter making her smile in spite of herself. After regaining her composure, she made her way to the main hall. "She always had a knack for bringing a ray of sunshine to even the most serious topics of conversation. I will miss her witticisms." She put the hoof on a panel. The door turned to mist. She walked through and stopped at the entrance. "Girls, this is the old Sandmare Project."

Sunset and Rainbow entered the room. The former just sat next to Spitfire. The latter went over to the centre of the room, looking at two pegasus dummies of both genders. On both were prototypes of armour without protective plates.

Rainbow tilted her head towards Spitfire." What's this?"

"More specifically, what was Project Sandmare?" Sunset corrected.

Spitfire looked at them before wandering around the hangar, going from bench to bench, from schematics-covered countertops to those with metallurgical studies. "It started shortly after I became chief of the Wonderbolts. At the time, I was obsessed with an idea: What if somepony like Sunpest goes rogue and threatens the safety of Equestria?"

"Oh, so you were obsessed with me? Interesting," Sunset said with an impertinent smile.

Spitfire continued with a brief, knowing smile. "The worst thing about it is that I wasn't the only one in this case. Several high-ranking Wonderbolts were literally obsessed with the idea, day and night. In our dreams, there was a unicorn—sometimes a male, sometimes a female—sometimes a relative, sometimes a stranger—but always a unicorn who was going to be an unstoppable threat to us pegasi. So we started working on this project. In time, we found a metal that was impervious to magic. Only trouble was, it turned out that the samples of this metal came from meteorites. Soon after, the obsession evaporated. Dreams, ideas— just poofed away overnight, as if a page had been turned without our knowledge."

Sunset wondered if Nightmare Moon had anything to do with this, but saw no point in pushing the enemy to do research to fight a unicorn or an alicorn. She kept that idea in the back of her mind for the time being.

"How many have you collected? How much armour could you make out of it?" Rainbow asked as she tried on the helmet, which was designed to follow the contours of the face without obstructing vision in any way.

Spitfire came over to adjust the helmet's fasteners. "A few ingots of pure metal there under the tarp," she said, jerking her head to a corner. "Not even enough to make a full suit of armour," she said as she tied the chinstrap, half-strangling Rainbow in the process.

Sunset went to see said metal. The tarpaulin moved to the side, she tried to use telekinesis on one of the ingots, but it proved to truly be impervious to magic manipulation. She took the time to study the metal. It was so black that it seemed to absorb the light itself. She put the ingot down and put the tarp back on. Without too much difficulty, she found a study report on the metal. "Given its density, if one made an armour with such metal, it would drastically reduce the speed of the wearer."

You could be reading stolen content. Head to Royal Road for the genuine story.

"This is the major concern.Was metallurgy before or after ‘Sunpest, the righter of wrongs’?" Spitfire asked as Rainbow put her hooves in the solerets.

"Afterwards. When I first started there, I used a regular sword. But the more I learned about this country, the more I appreciated their customs and habits. I worked to accumulate favours with a clan until I could express the wish to make one for myself. To buy a blade, anypony can do that. But a katana is to brandish my honour, to show what metal I'm made of. At least that's how it's perceived over there in Japony."

Rainbow was both lost and fascinated by what Sunset said, but a physical sensation perturbed her more.She looked at the solerets in more detail, intrigued. "Is it just me, or am I taller?"

Spitfire smiled at Sunset's words, then turned to Rainbow. "Rear up and crush the front hooves as you fall back."

Rainbow obeyed without blinking, and, in doing so, activated an internal mechanism that released manticore-like claws. "Whoa, cool!" She looked at them for a moment. "It'd be, like, twenty percent cooler if we could use them to manipulate objects."

Sunset dropped the study notebook and came closer to see the fitting of the armature. She used magic to put the rest of Rainbow’s body and wings through it. "You look like one of those half-pegasus, half-metallic creatures from those science fiction stories," she commented before turning to Spitfire. "So, what's the project all about?"

"I have to finish Project Sandmare. Make this armour capable of facing a unicorn and put it into action. Any ideas?" asked Spitfire.

"It's been a long time, but what have you learned from our training?" Sunset replied.

"Even with the best mobility, whenever you used telekinesis to immobilise me, it was my defeat." She turned to Rainbow. "Any ideas, Dash?"

Rainbow wanted to bring her hoof to her lips, the prototype’s claws pricking her nose in the process. "Ouch!"

"To retract those claws, you have to click your heels together," Spitfire said.

One heel-slap later, Rainbow tried to find a memory of a one-on-one fight with a unicorn. But nothing came to her. "Not really. The one time there was a fight with a unicorn, I kicked her in the neck, but Twilight and Applejack were distracting her." She sighed. "It was Pepper."

Spitfire put a hoof on Rainbow's shoulder. "I've read the report. Dash, you couldn't have known what she had in mind." When she saw that she failed to cheer Rainbow up, she turned to Sunset.

Sunset looked up at the sky and smiled. "Hey, Rainbow. I forgot—what's the name of the project again?"

Rainbow looked up at Sunset. Though caught off guard, she laughed unwillingly. "All right, all right, I'll keep smiling. Anyway, what about the armour?"

"The armour will always cause you to lose speed. We must reconsider the concept if we try to make a lamellar armour like that of the Royal Guards. Their armour is made of iron, which wouldn’t allow a pegasus to lift off. No, it would be better to make something like chain mail, or an equivalent like a kikko. The meteor metal would be underneath the armour and block telekinesis, so the wearer could concentrate on flying around to dodge enemy attacks."

"Kikko?" Spitfire asked.

"Imagine lots of hexagonal metal plates no larger than... a square of four stamps, all sewn together over the entire surface of a thick, cloth suit," Sunset explained.

"To the extent that we're talking about creating a virtual anti-telekinesis bubble, we could remove the cloth outfit and weld these plates together inside a complete cloudichalcum armour," Spitfire proposed.

"Cloudichalcum?" Rainbow asked.

"Light as a cloud, stronger than the best steel. It is the metal used for the princesses' regalia. The only one that can withstand their power without ever being damaged," Spitfire explained. "Sometimes I find it hard to believe that princesses have been wearing the same regalia for a thousand years. Yet, it just goes to show how much metal has survived the centuries without a scratch," she added in a whisper.

"So we're talking about making armour like the princesses’? Cool!"

Sunset had an amused smile. "Technically, even better than princesses’." She gave herself a moment to think aloud. "Tests will have to be conducted. The main concern would be to determine exactly how thick the plates must be to make the Wonderbolt wearing the armour impervious to telekinesis."

"She," Spitfire said. "Dash joined the active team yesterday. It remains to be seen which one will be ready first: the armour or the soldier," Spitfire thoughtfully said.

"Wait, what?! Me?!" Rainbow asked, taken aback.

"Yes, you, Rainbow Dash. Why do you think you're here?" Spitfire said.

Rainbow was frozen in awe. She couldn't believe it; her dream was coming true. She was no longer a reservist; she was now a real Wonderbolt. She had imagined that, when this moment came, she would smile up to her ears, crying in joy, taking off into a Sonic Rainboom. Yet, somehow, she felt crumpled. And as Spitfire went into detail, one question nagged at her mind . "I became a Wonderbolt, yes—but at what cost?"