Twilight Sparkle collapsed on the castle floor beside her drafting table, her mane a shambles, her one natural eye bloodshot. And still, yet another unicorn with a request: "Page 4 of the antimatter containment unit assembly instructions says to use a 'tool 45853.76' on the sprocket seal, but none of us in Team B can find the specs for how to fab one."
Shakily, Twilight pushed herself up into a sitting position, then used her left foreleg — the artificial one, the only limb that wasn't exhausted — to pull another sheet of sheepskin into position. The last of the parchment had run out hours ago. She looked up section section 45853.76 in the Borg's general tool reference, engaged her horn for what must have been the two thousandth time, and flashed her thoughts into printed reality. The page was smudged and a little blurry, but it was the best she could do. "Scribe," she croaked, and another royal assistant trotted in, took the page, and galloped off to make copies. She squeezed her eye shut and rubbed it, trying to stay conscious.
Princess Celestia came in to check on her. Again. "You can't keep this up, my faithful student. You've got to sleep some time."
Twilight glared at her princess and mentor. "You know I can't do that. You saw how many new pages I've had requests for in just the last hour alone. Every minute I sleep is a minute some new construction snag can't get resolved."
"The teams can work around those snags," Celestia tried to soothe her, "Or if they can't, they can work on some other part of their project until you can get them the new page. You just need to have faith in them."
"Faith," Twilight snorted. "I had a feeling from the beginning that this would be impossible. The Borg have assimilated other spacefaring species, and I took a look at how long it takes some of them to build a starship. A construction project of this magnitude typically takes months, and that's assuming that all the parts and tools already exist and that the species has had experience building the same ship in the recent past. Let's face it, we're biting off way more than we can chew here."
"Well if you take that attitude," Celestia scolded her, "If you expect failure, then you will fail. Again, faith!"
Twilight growled, "You know, Celestia, you can be really condescending sometimes."
For an instant, Celestia's eyes flashed at this offense. Then she regained her regal bearing and said, "You're really tired. You need to sleep. The reason you're saying such a thing is because you're horribly cranky right now."
"No it's not, Princess," Twilight spat out the word. Her eye narrowed. "I've never forgiven you for how you handled the whole Nightmare Moon crisis."
Celestia was taken aback. "Forgiven me?! Equestria was saved! And you learned the power of friendship!"
Twilight shook her head. "You did everything in your power to put Equestria in as much peril as possible. You knew Nightmare Moon was coming back! You could have moved the five Elements of Harmony to Canterlot for safe keeping, but instead you let them rot in the ruins. You knew you'd need the power of friendship, right? You could have lined up an army of ponies who already had friends, and had that power at your disposal in an instant! You knew that when Nightmare Moon appeared she would use her powers to deceive, and you could have warned everypony. But what did you do? You relied on me — a reclusive bookworm with no friends at the time — to know exactly what to do, and to find a group of friends that could pass each and every one of Nightmare Moon's tests. Did you even stop to think, for one moment, that if any one of us had failed to come through, your whole plan would come crashing down and Equestria would have been plunged into everlasting night?! Have you even considered the consequences of everlasting night?! Plants need sunlight to live! Moonlight isn't enough! Every tree and bush in Equestria would wither and die in a matter of weeks, and then everypony would starve. Is that how you look out for the best interest of your subjects, Your Majesty?! Good gravy! If Rainbow Dash had been just a little more interested in the Shadowbolts, your plan fails. If Pinkie Pie had been just a little more scared of the Everfree Forest, your plan fails. If Applejack hadn't noticed Dash and Fluttershy swooping into position when I was hanging onto that cliff, your plan fails. If even one single event had not gone off as expected, your plan fails!"
Celestia hung her head in anger and grief, then blinked with understanding. "And now," she said in a low voice, "You are in the same position I was. To save your friends from the Borg, your plan also requires everything to go just right."
Twilight crumpled into a heap and sobbed. "Yes!"
Celestia covered her faithful student with one wing. "You're right. I did make some bad decisions. In hindsight, there were a lot of things I could have planned better, and I'm lucky that events played out as well as they did. Some of the grievances you brought up just now have also crossed my mind, and I've kicked myself more than once for not having thought of them beforehand. But I'll let you in on a little secret. Every single decree I make as Princess carries with it the same burden you're feeling right now. There's not a day that goes by where I don't second-guess myself, where I don't wonder 'would things be better now if I'd decided the other way on this, or that, or the other royal order?'. Even after a thousand years of rule, a thousand years of seeing the consequences of my decisions play themselves out on the stage of Equestria, even with all my experience it still comes down to making one educated guess after another and hoping I get it right."
"Holy cats," Twilight swore. "You mean every time I take command I'm going to get this, this same knot in my stomach that I feel right now? And it's never going to go away?"
Celestia smirked. "I've gotten used to it. In fact, that knot in my stomach is almost comforting. It lets me know I'm fully involved, and that the decision matters. In fact, I get worried when I don't feel that knot in my stomach, because it usually means I've missed something important."
Twilight stood back up, took a long breath, and stared at her drafting table.
"And now, I have one more royal decree for you," Celestia said. "Go. To. Sleep. Trust your people to continue their work for the next several hours without you."
"But what if —"
"That's an order. No interruptions. I'll post a guard to make sure you're not disturbed. Don't worry. If there's a real emergency, I'll wake you. Now go."
Twilight bowed, in royal deference and, internally, in relief. "Yes, your highness." Then she turned and walked to the adjoining alcove where her bed lay.