On the next morning, Sunset is watching Sunrise play on the citadel's lake, thinking what could be the filly story, how she ended here when HAL's voice sounded on her watch.
"Captain?"
"Yes, HAL?"
"I have some news."
HAL's voice sounded apprehensive, so Sunset supposed that isn't good news.
"Meet us in ten minutes."
Ten minutes later, they all are on the citadel's hub and even HAL not having a real face, Crystal and the other sensed that something wasn't right.
"I was running a series of simulations on Harmony One, and I think I have an answer to you all"
HAL opened her hand and put a small holocube on the ground, which started to show a series of equations and simulations.
"As we saw yesterday, the same energy was found in all of your incidents. I used the Citadel's data and my own to find some correlation."
"And I suppose you don't have good news."
"Yes and not, Starlight. I didn't discover yet what caused the end of parallel Equestrias, but I think that I found a way to sort of restoring your worlds."
"This doesn't seem bad."
"But is, Nova. We can restore your realities by sending a huge harmonical blast across the multiverse blowing up its nexus point. This way harmony would fix everything and you will not even remember that your worlds ceased from existing."
"But this isn't the bad part, right?"
"Unfortunately no, Crystal. According to my calculations, we have to blow up with the citadel, since she is the contact point from all multiverse."
The holocube showed the citadel exploding and the explosion multiplying several times, meaning that was being replicated through the multiverse.
"And since you and Sunrise are part of the citadel, both of you will die, and even if one or both of you somehow survive, will be dragged to a non-existent universe, a void between realities, without a chance to rescue, since you would be erased from existence in all realities, universes, and timelines."
The room sat in silence.
"I'm sorry, I hope I have better news."
Sunset walked and put a hand on HAL's shoulder.
"It's ok, HAL, at least now we know what to not do."
Sunset is closer to the citadel's gate when Crystal finds her.
"Are you leaving yet?"
"Don't think you will be free of me too soon, Crystal. I just had an idea and I need the Harmony One computer to test it."
"So, you aren't ready to blow up me and Sunrise to save your Equestria?"
"If this is the cost to bring my friends back, I prefer to not do."
Sunset lets out a burst of laughter.
"Twilight and the princess would punch my face if they knew that I choose them instead of you and an innocent filly."
"Mom?"
"Yo, Dawn. I'm going to Harmony One for a while. Wanna come?"
"You aren't considering accepting HAL's solution, are you?" asked Dawn concerned.
"Not even for a second. Your mom would never forgive me if I did it"
"Yeah," Dawn said letting a relieved breathe escape her mouth.
"We will find another way, I promise." said Sunset putting a hand on Dawn's shoulder.
"Hey, where is HAL?"
"He is on the citadel's hub discussing possible solutions with Steve and the Citadel."
"Good. Well, I gotta go. Call me if you need something."
Sunset crossed the portal and saw the Harmony One landed less than 20 feet from the gate.
"I can't say that is a surprise see you here, captain." HAL's voice sounded from Sunset's watch while the landing ramp of Harmony One was opening.
"You know me, HAL, I don't give up so easy."
"Yeah, you wouldn't be the Sunset I know if I gave up on the first hurdle."
Sunset entered and touched the walls of her ship.
"You did an amazing job, HAL, the ship is good as new."
"Thanks, captain, but I can't take all the credit, great part of the success is thanks to admiral Twilight's wonderful engineering."
"Yeah, she is, was amazing." said Sunset feeling her heart tightens.
"HAL?"
"I'm ready, captain."
Sunset enters Harmony One's tech lab and sees that data are being projected on all the walls.
"Let's do it."
About five hours and a lot of simulations later, Sunset thought that she finally had something.
"Ok, what if we enhance the energy input by 7.52 percent, and reconfigure the secondary shield in minus 38.71 hertz?"
"Even so, we will not have enough thaumatical energy."
"How much we need?"
"More 1,21 gigawatts of thaumatical energy."
"Okay."
Sunset inputted new parameters at their equations.
"Run simulation 271-a"
"My first directive is to protect Harmony One's crew, I can't run this simulation, captain."
"I'm sorry, HAL. Requesting access level omega. Identification: Admiral Sunset S. Pie. password: pinkamena."
"Request of access level omega accepted."
"Run simulation 271-a, ignore the primary directive."
"The simulation shows 99,17% of success with the new parameters."
"Start conversion of primary warp drive."
"As you wish, admiral Pie."
"You already modified Harmony One's warp engine to act as an interdimensional drill, so with some alterations, we probably will be able to send the energy through the multiverse." Said Dawn
"Makes sense." agreed HAL "We only will need a harmony energy source"
"So, where we can find one?" asked Steve.
"Well, that's the problem. As you probably know, in every Equestria that the citadel made contact, the elements along with the harmony magic are completely gone."
"So, there's no chance to save Crystal and Sunrise, it's it, HAL?"
"And you, Citadel, but no, still there's a chance to save you all." Said Dawn
"Sunset." said Nova "Your mother is the source, isn't Dawn?"
Dawn lowers her head and clenches her fists.
"She absorbed the elements from our world, so she's the only know source of harmony's magic"
"I see we came to the same conclusion" said Sunset entering the room, while HAL feels a little dizzy and shakes slightly her head.
"HAL is already modifying one of Harmony One's engines, so maybe tomorrow we will be ready."
"You can't be serious! How in Celestia's name you could even consider this an alternative?"
"Starlight, don't you want to see all your friends again?"
"Of course I want! But not if it costs your life!"
"The 'bomb' will only drain all my magical essence, so I will not die. Probably."
"Admiral, your chances of surviving is only 7.03 percent."
"Yeah, HAL, you already said that. But the chances of success of this plan are above 99 percent. come on, girls, have a little faith"
"Sorry, Sunset, but we can't take this risk."
"Starlight is right. We will not sacrifice someone to save our world. We do not even know what caused that event."
Sunset felt something grabbing her leg and looking down saw Sunrise hugging her.
"Please, don't do this. I don't want to lose you."
Looking at Sunrise's face, Sunset saw something, that little girl, she would prefer not to know her story then lost a friend, which makes Sunset remember the memory stone incident. She then kneeled down and holding Sunrise's head with both hands, planted a kiss on her forehead.
"Don't worry, I will not do anything stupid, we will find another way."