//------------------------------//
// CH19: Backup to the Backup 
// Story: A Dubious Welcome 
// by Maonyman 
//------------------------------//

Starlight Glimmer was pouring over a dusty tome found near the cursed portal site when she once again heard the Royal Canterlot Voice ringing through the castle.
"STARLIGHT GLIMMER, COME TO ME NOW."
With a startled yelp, the tome flopped to the ground and she hastily righted it before teleporting into the foyer.
"Y-Yes Princess! What is it? Is she back? Is Twilight back!?"
Luna peered down at her with a somber expression and said, "No, little one. I fear my sister is in trouble now, too."
"What!? How?"
She shuddered to imagine the creature that could defeat even Celestia herself.
"I do not know. The connection of our life force is a vague and imprecise spell, albeit an extremely hardy one.
Starlight stared at her, half shocked by the news, half mesmerized by the iridescent shimmer of her billowing mane. Then she realized Luna was politely waiting for her to regain her composure and shook her head in an attempt to snap out of it.
"Oh, um, sorry. So... what do you need me for?"
"Because I need your help."	
"My help!?"
She tried to suppress it, but a snort of incredulous laughter snuck out before she got control.
Luna only smiled in response and said, "Yes, Starlight Glimmer. I want you to save Celestia."
There was a beat of silence. Then she gave Princess Luna a wry grin.
"Oookay, yeah, very funny."
Princess Luna merely stared at her.
"I-It's a joke, right? You're joking."
"No, Starlight."
"What do you mean, no?"
"I am completely serious."
"B-But...!"
She stared up at the glorious image of her princess staring down at her, and tried to come to grips with the conflicting thoughts going through her head.
"No, no no no, you're actually serious!"
The Princess nodded gravely, and Starlight's voice began to take on a note of hysteria.
"Something got Twilight, then got Celestia, and you want ME to stop it? What am I supposed to do about it!? You're a whole order of magnitude stronger than me, you could probably disintegrate whatever is out there, a-and I'm just me! I-I can't--"
"Starlight!" Princess Luna barked, startling her into silence. "I am not sending you empty hooved. You will have more abilities and more power by combining the effects of multiple artifacts not permitted to most ponies." She glanced away and added quietly, "As for me... I may not leave Equestria unguarded and without a leader. I must stay."
"You... but I..."
"Do not sell yourself so short, little one," The Princess said gently, "With Twilight's ascension to alicorn, you are very likely the most powerful unicorn in all of Equestria, and certainly within the top few. We shall bolster that strength and make you even greater still."
Princess Luna straightened proudly, seeming to swell before her.
"With the true power of the throne at my disposal, I may command certain forces on your behalf. Combined with the right amulets and preparatory spells, you will become nearly as powerful as me."
The walls reverberated with the echos of her voice, and Starlight, who was feeling very meek in her awestruck daze, could not help but feel a bit of pride herself.
"You will go forth into that strange world. You will strike down the monster, whatever it may be. You will bring my sister and her pupil, your own mentor, home. We begin preparations at once. Come!"
Her horn glowed like the sun as she teleported them both to the Canterlot palace.
Spike stirred slightly from his nap, then mumbled something and turned over.
*	*	*
Starlight shivered as yet another wave of cold washed over her.
"Are you s-sure this is r-really necessary?"
Princess Luna paused in the ritual, holding the seemingly empty bowl above Starlight's head.
"I am sorry, little one, but yes. Once finished, you will possess nearly unlimited magical energy for the duration of one day. We cannot have you sparking out, now, can we?"
Starlight sighed, "N-No, I suppose not."
The Princess's horn flashed a dim cyan color, then she poured yet more freezing air out of the bowl and across Starlight's back.
"I think we are almost done, however, and this is the last artifact we will be using."
"Oh, b-but I was just s-starting t-t-to enjoy m-myself."
Another burst of cold poured over her back and then, just as Starlight was certain she would pass out from the cold, Princess Luna gave the signal, "Now, Starlight! Now is the time!"
She stumbled forward and thrust her horn into the jelly-like mass on the pedestal. It had been cold when she touched it earlier, but now it felt warm. Actually, was it getting warmer? Yes, it was definitely getting quite warm. Hot now, painfully hot. She reflexively tried to pull out, but her horn seemed glued in place. It was burning now, but her voice was silent, her hooves locked to the ground.
Then abruptly, liquid fire rushed out from her horn, flowing through her in an instant. She gasped and collapsed to the ground, her horn finally released from the strange jelly artifact.
Princess Luna's face immediately filled her vision.
"Art thou alright? Er, ahem--Are you okay, Starlight? Did it work?"
"Mmmphr..."
Her body felt strange, like it was too small for her mind. A spark shot out of her horn and Princess Luna casually brushed it aside with a flick of her magic, looking suddenly excited.
"That is a good sign!"
"HnnnNNNG!"
She was being crushed inside her own skull. The pressure had to be released and there was only one way out. Princess Luna's head moved out of the way just as a blast of light burst out of Starlight's horn. The world now seemed unnaturally bright, everything was white-washed, and... she was floating?
She was vaguely aware of the Princess shouting something below her, but the rushing in her ears drowned her out. Suddenly she heard Princess Luna's impossibly loud voice seemingly coming from inside her own head.
"Starlight, remember!  You must stem the flow! It will feel impossible, but it will fade quickly if you hold on! Do not let it run free!"
She struggled to follow the command, but the pressure was immense and the world was growing brighter still.
"STARLIGHT GLIMMER, HOLD THY MAGIC."
The Royal Canterlot Voice triggered the deeply ingrained instinct to obey your Princess and a guttural scream tore from her throat as she seized the flow of energy, halting it in its tracks. She slumped to the ground and the brightness faded, but the pressure was unimaginable--her head would explode!
"Hold Starlight! Just a few seconds!"
Seconds? She'd been here hours already. Her skull was splitting with the forces inside her, yet somehow she held. Every ounce of her being was focused in the tip of her horn, feeling like an ant before a waterfall, yet she refused to budge, holding back the inexorable tide.
Then it was gone.
Her head whipped back as the pressure vanished in an instant and she fell heavily onto her rump. She began to slump sideways until Princess Luna cradled her in her magic, helping her sit straight. Starlight looked up to see a broad smile across her muzzle.
"Well done, very well done! I was becoming quite concerned, but you have pulled it off!"
"Never... again..."
Princess Luna nodded as she gently released Starlight, and although she was still panting from the effort, she could feel the Princess was right: her horn practically buzzed with potential energy, far more than Starlight had ever felt before. Cautiously, she reached out to float a small stone nearby. It rose exactly as she expected. No rocketing away, no explosion of wild magic, no glowing eyes.
"Oh good..." Starlight murmured, "The Ring of Laminus is working."
"Indeed! You are very nearly ready. You need only cast the protective spells now."
Starlight nodded and focused her magic, giving herself every ward she could think of: burning, freezing, piercing, crushing, sapping, blasting, all of them. She even had a ward against sneezing. Next was a neat little spell which allowed you to charge a piece of jewelry--an earring in this case--so that whenever the wearer loses consciousness, a small yet powerful shield of both stealth and protection gets projected around her.
Finally, following the spell's instructions very carefully and keeping Princess Luna's advice in mind, she attempted a regeneration spell which was easily the most convoluted piece of magic she had ever attempted. Neither were surprised when the first attempt failed and, undeterred, she tried it again. This time it seemed to work, but when she tested it with a small nick on her hoof, it only bled like normal.
Rather than try the same thing a third time, she went over the instructions again with Princess Luna's help, searching for anything she had missed. Eventually they found one tiny harmonic thread she had overlooked, and felt ready to try again. 
This time, the little cut healed instantly.
"Yes! Haha, take that Twilight! She could never get that bucking spell to work!"
"Indeed, well done. It is phenomenally tricky. Of course, Tia would likely make it look as simple as telekinesis, as she did with all healing magic."
"Wait, really? Then why is she... er, I mean--"
"That is why I am so worried for her, Starlight. She was healing for a time, then simply... stopped. Then her condition began to slowly deteriorate. I fear she is wasting away. 
Starlight shuffled her hooves in anticipation. She was anxious, yes, but also quite looking forward to utilizing all this power she had acquired.
"Well, then what are we waiting for? I'm gonna go save me a pair of princesses!"
"Do not forget the spells we went over!"
"Oh don't worry, Princess, I got them. One for Celestia, one for Twilight, and one to contact you."
"I only hope they will be within range."
"I'm sure they will. I mean, the spell reaches twice the size of all Equestria after all!"
That seemed to amuse the Princess and she said, "Equestria is only a small fraction of this world, Starlight. There is still much beyond our borders, beyond even the griffons and dragons."
Luna smiled down at her then, a genuine smile that filled her with joy and pride that she could help her Princess.
Then the alicorn lowered her horn, focused briefly, and with a yank of her head, she ripped open the fabric of the world, summoning that ominous blue portal. Princess Luna stood before it for a moment, clearly yearning to enter it herself, but finally, she stepped aside to let Starlight pass. 
As the unicorn approached the portal, she twitched her withers to activate the magical saddle so she floated gently above the ground. She preferred flying herself around with her magic, but she would need her horn free for other spells, and this was faster in any case.
"Good luck, my little pony."
Starlight smirked, "I don't believe in luck."
Princess Luna lowered her head and looked her in the eye.
"Well then believe in yourself. I certainly do."
Starlight beamed at her Princess, then she slowly floated through the portal.