Author's Notes: Once again, the response to the last chapter has astounded me! And yes, we're getting very close to the end now...not much longer is left. But how will it end? That, my friends, will only be answered by reading on!

Before I let you go, though, I must send a massive thank you to "Mauritaly", who made an amazing little image in tribute to this fic, completely out of the kindness of their own heart! Words can't express how much I appreciate the gesture, but thank you, all the same, it's amazing!

Now, then, on with the show...

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Chapter 47

All or Nothing

Twilight rapidly picked up on Starfall's sudden spark of hope, her own face showing that same eager hope as she smiled at him. "What? What is it, Starfall?" she asked, all her friends crowding around as well, eager to find out about whatever brainwave Starfall had just been given.

Starfall looked up at them. "A while back, I once caught Cosmo hanging around near the wall to the Royal District, where it merges with Canterlot Castle. It was raining that morning, meaning he wouldn't have been there without a reason...except there's nothing but residential houses there. I wondered what he was doing loitering there...and now I think I know. I think he found a secret entrance...some kind of back door into the castle there! I think that's how he got in, and if I'm guessing right, he might not have thought to seal it off...or deliberately left it open. I doubt he wants to die here with the rest of us, and so will have some kind of escape plan."

For a few moments, none of the six mares said anything, just staring at him for several moments. Twilight was the first to recover, once more bouncing forward to give Starfall a big hug. "Starfall, you're a genius! That must be it! Cosmo must have found something by that wall, a secret passage leading into the castle!"

Starfall smiled, his eyes narrowing slightly as he turned towards the road leading out of the Royal District, near where he had seen Cosmo on the far side. He spared a quick glance up at the sky, pausing as he noticed the comet had come noticeably closer. The faded stars had dulled the night sky's appearance, making the comet even more prominent as it streaked towards them...Starfall guessed that they had maybe fifteen minutes...if that.

He shook his fear off, knowing he had to focus...they had no more time to lose. "Come on, we have to get back inside!" he called, starting to gallop off, before pausing, noticing the six mares were instead fixing to head the other way, Twilight looking over her shoulder at him, catching his confused look.

"There's something we need to get first, Starfall!" Twilight called to him. "Something we have hidden away that can stop the comet before it's too late! Go on, Starfall, you need to buy us as much time as possible! We'll be right behind you!" Starfall hesitated, wanting to know exactly what they were doing, but Twilight urged him on. "There's no time to explain, Starfall! Go!" she cried, spurring him into action, turning back around and galloping away, knowing that from this point on, every second counted.

Spotting Archer, who had been lost in the crowd, racing to catch up to him, Starfall paused, turning back to her. "Archer, listen to me. I want you to go home, get to your family, and try and convince them to leave Canterlot, as fast as you all can," he said, holding up a hoof to stop the filly's protest. "I know you want to help, but trust me, you'll be helping me more than you can realise by getting yourself, and your family, out of here. I'll try and buy you as much time as possible."

"But..." Archer tried to protest further, but Starfall shook his head. He could not let her, still such a young filly, into such a dangerous situation.

"Archer, where I'm going, there's a good chance ponies will be killed...please don't make my effort to save you all those years ago be in vain now. I can't stay around to warn everypony of what's about to happen...but you can. You've already done so much...you gave me hope again, and I can't thank you enough for that. Can you do this for me, now? Can you go to your family, and warn everypony you see along the way?" he begged of her.

Archer finally seemed to understand, swelling herself up with pride at the idea of being able to do something important. "Just hurry, Starfall...I know you won't let us down!" she said, before galloping off, leaving Starfall alone once more as he raced for the spot where he had seen Cosmo all those months ago. There had to be something there...there just had to.

But, once again, he did not get very far before a familiar couple called out to him. "Starfall! What's going on? Where are you going?" Princess Cadance and Shining Armor, seemingly exploring the outer perimeter of the castle, trying to find a way in, abandoned their search to chase after Starfall, once it became apparent that the young pegasus was not slowing down.

Starfall made to call out to them once they had caught up, but Shining Armor beat him to it. "We were outside the castle, checking on the security when the whole place just sealed up...we haven't found a way passed it yet, and have no idea what's going on, but we saw what happened with the stars and the comet. It's bad, isn't it?" he asked, seeing the grim, determined look on Starfall's face.

The yellow stallion nodded, before going into a quick explanation, briefly going over Cosmo's appearance, Luna's corruption back into Nightmare Moon, how she had defeated Princess Celestia while Twilight and the others had been teleported out of the castle, before finally describing Nightmare Moon's impressive magical display that was bringing the comet down on top of Canterlot, along with the fact that they had well under fifteen minutes left now.

"I remember seeing Cosmo hanging around the wall to the Royal District next to the castle a couple of months ago...I'm sure he was scouting out some kind of secret passage into the castle, preparing for just this sort of thing," Starfall finally concluded, never even slowing down in his desperate gallop, finally passing through the gates out of the Royal District, immediately swinging back around towards the castle.

Cadance called out as they kept running, responding to his tale. "I think I remember hearing various rumours about such a passage...some of the guards refer to it as the Commoner's Gate, but nopony's sure if it actually exists, or whether it's just an old mare's tale, to give the common Canterlot citizen that feeling of having some small access to the Royal Palace."

Shining nodded his agreement. "The guards talk about it all the time...but I've never had it's existence confirmed...and I'm supposed to know every secret passage the castle has," he added, frowning. "Are you sure that's what Cosmo was there for, Starfall?"

Starfall nodded. "It's the only reason that makes sense...there has to be something hiding there, Cosmo had no other reason to be there at the time...he wouldn't go out in the pouring rain just to take a random stroll, even if he can create a magical umbrella at will."

But Starfall stopped, looking around, quickly recalling the details. "This is it...he was here when I saw him...the entrance has got to be around here somewhere..." he said, already starting to look around, focusing his attention on the wall, where he could see the castle rising up directly behind it. This was the spot...the best place to hide a secret passage to the castle that was accessible to general Canterlot.

Shining Armor, still seemed sceptical, but after sharing a look with Princess Cadance, who seemed to have a bit more faith, he finally shrugged, joining in the search with her, fanning out to try and inspect the wall, looking for any sign of some kind of secret passage, Cadance and Shining even using their magic, their horns flaring as they seemed to scan the wall...likely looking for any kind of hollow points or unusual markings that would alert them to the possibility of some kind of hidden room or passageway.

But Starfall grew frustrated quickly...they could not afford to waste time searching for it, and as Shining and Cadance's efforts turned up no results, he growled and turned away from the wall, glancing up at the sky...the comet was still closing in. They could not have much more than ten minutes now. If he did not find the passageway soon, it would be too late.

But as Starfall looked back down, intent on doing another sweep, something caught his eye. One of the houses next to the wall did not match up with the design of the rest of them, looking significantly older, almost ancient. As Starfall trotted over to it, he noticed that the house was covered in cobwebs and dust, and the paint appeared to be peeling away from the walls. It had obviously fallen into disrepair, likely abandoned for some time.

As Starfall moved a little closer, he saw that the front door had a simple notice tacked onto it, a simple warning that the house was dangerous, and that nopony should enter. The notice had been signed by Princess Celestia, and appeared to have been left there before Starfall was even born. From this distance, Starfall could also feel the slight tingle in the air, making his fur stand on end, feeling a little like a vague static charge in the air...strong magic was warding this door, and the entire house, really.

But as Starfall leaned in for a closer look, he spotted something that made his breath catch in his throat. "Cadance! Shining! Come here for a moment! I think I've found it!" he yelled, hearing hoof beats immediately follow his call as the newly-weds raced to find him, clearly hoping he had found the entrance they were looking for.

"What is it, Starfall?" Princess Cadance called once they reached him, looking up at the abandoned house. "Oh...this has been like that for as long as I can remember, nopony ever seems to do anything about it."

"This is just another abandoned, warded house, Starfall," Shining Armor said, sounding a little disappointed. "Everypony knows not to go near these kinds of places, now come on," he said, about to walk off, only for Starfall to gesture rapidly at him, getting him to pause.

"Wait, Shining. You said everypony knows to avoid these, and I feel the magic sealing it from curious ponies, but if that's the case, how do you explain this?" he asked, pointing to the door, specially the doorknob, before gesturing down the edge of the door, and finally to the gap in the floor directly underneath the door itself.

As the young couple took a look, themselves, they froze, Cadance giving the smallest gasp as they both saw what Starfall had seen. First, while the whole door was covered in dust and cobwebs, the doorknob, while still looking dull and rusted, was clean, suggesting somepony had touched it...very recently. The door frame from the next port of call, and again, a sign of something being amiss, the edge where the door swung away when opening showing signs of having cobwebs covering it, only for them to have been broken recently, which could only mean somepony had opened the door.

And finally, there were marks in the dust lying in the gap underneath the door...clean patches on the floor of the doorway. That was the final piece of evidence...not only had somepony managed to get the door open, but they had also gone inside the building.

Shining was the first to respond, seemingly stunned. "But...Princess Celestia herself saw to the wards surrounding this building. The magic needed to get past them would be...immense," he said softly.

Starfall frowned. "The dark magic Cosmo's been influenced by would almost certainly be strong enough," he said, his voice low. "Can either of you break through it?" he asked, looking between the two of them.

Cadance gave a small nod, stepping forward. "I know how to dispel these wards. One moment..." she said, before closing her eyes, concentrating as her horn flared to life, the pale blue magical aura swirling to life, drifting from the tip of her horn towards the house, stopped when a layer of golden magic flared into view, the wards reacting to Cadance's magic as she tried to circumvent them and allow them to enter the house.

It took several long, agonising moments, that felt like hours to Starfall, but eventually the golden aura around the house faded, Cadance letting her own magic fade away, taking a moment to catch her breath. "That should do it, we should be able to enter, now," she assured them.

Starfall nodded, approaching the door carefully, slowly reaching a hoof up to the doorknob. When he touched it, and felt no magical presence trying to force him back, he steeled himself and opened the door, peering inside the gloom of the house. As he expected, the place was barren and run down, filled with dust and cobwebs, what little furniture there was laying moth-eaten and half destroyed.

It looked just like any other abandoned house...but Starfall knew this one was different, it had to be. "There's got to be something here," he muttered, looking around, trying to find any sign of some kind of passage that would lead down and under the wall, back to Canterlot Castle.

Before he could really even get started, though, Shining Armor did a quick scan with his magic, the magenta glow soon fading away as Shining's eyes lit up. "This way!" he called, leaving them over to the far corner of the main living room, Starfall and Cadance following on after him.

Sure enough, there in the corner, looking like it was supposed to be concealed under a rug that had long since turned to dust, was a simple wooden trapdoor, concealing what must have been some kind of passageway down underneath the house.

"As far as I can tell, the tunnel beneath this trapdoor heads back towards the castle," he said, giving Starfall an impressed look, clearly proud that the young stallion had worked out the secrets of this passage. "There's no time to waste! If we don't hurry, Cosmo and Nightmare might decide they've lingered long enough and leave!"

But just as Shining lifted the trapdoor with his magic, and was about the clamber down the stairwell that was laying underneath, Starfall lifted a hoof. "Shining, wait. Twilight and her friends had to detour...said there was something they needed to get first. They'll need somepony to guide them to this house when they catch up," he warned, making Shining pause.

The Captain of the Royal Guard quickly made to protest, but Starfall cut him off. "Not only that, but if I...if I can't stop them," he continued, stuttering at the thought of what that possibility meant. "Then Cosmo might not be expecting any pony to be waiting for him back on this end. You should be able to catch him off-guard if you do. Besides, we can't let any innocent ponies accidentally find this place, now that the wards are down." Seeing that the unicorn stallion was still on the fence, Starfall grimaced. "Please, Shining. I...I need to do this. I have to believe Luna can still be saved from the darkness...that both of them can..."

Shining finally sighed. "I don't like this, Starfall...it will be dangerous going back in there alone. I'm a trained Royal Guard, I really should accompany you," he offered, looking back at Princess Cadance. "Cadance can stay and wait for Twilight and her friends."

Starfall grimaced. "I know it's going to be dangerous. But I have to try," he said, full of soft, understated conviction. "Me and Cosmo have a history...it may be the best chance to turn him away from the darkness before it's too late. And Luna...she, well..."

Starfall was saved from explaining that rather awkward admission all over again by Cadance nodding softly. "I don't like this any more than you do, Shining...but Starfall is right. He's the best chance we have left, and he would probably have a better chance on his own. Let him go."

Shining looked at his wife for several moments, as if trying to muster up the conviction to protest her words, before seeming to give in, sighing even as he gave her a tender smile. "Alright...we'll do it your way, Starfall," he relented. "But the second Twilie and her friends get her, we're coming in for you, alright?"

Starfall nodded softly. That had been the gist of his plan, anyway, so he was not going to protest it in the slightest. "Thank you," he said to them both, before turning back to the trapdoor, steeling himself as Shining Armor and Princess Cadance wandered back outside, to wait for Twilight and her friends to come looking for him.

This was stupid...this was crazy! He was about to sneak into Canterlot Castle, to confront Cosmo and Nightmare Moon, who were both filled with a powerful, dark magic. Part of Starfall felt like he was about to undertake a suicide mission, that this night would be his last...but he ignored that fear as best he could, trying to keep his resolve strong. If he did nothing, death was a certainty. This way, he had a small chance of not only surviving, but saving the lives of thousands of ponies. To him, that made the risk worth it.

Taking a few deep breaths, mentally urging himself on, reminding himself what was at stake, and what the price would be if he failed, or took the coward's way out, Starfall finally moved his hooves, stepping cautiously down the staircase, into a small tunnel that had been carved in the stone beneath Canterlot, underneath the abandoned house.

Interestingly, the tunnel was lit up, small, magically-powered silver light glowing faintly within small containers fixed to the stone walls...clearly Cosmo's doing. This was definitely the right place, giving Starfall more confidence as he hurried down the tunnel, remembering that they were on a strict time limit. How much time was left? Twelve minutes? Ten? Seven? He was aware that the adrenaline in his system was messing up his sense of time, and without any view of the comet above, he just had no way of knowing.

The tunnel was too confined to allow Starfall to break into a full-speed gallop, so he was forced to settle for a swift canter, keeping an eye out for any sign of any branch tunnels or other unusual things, wary that Cosmo might have left traps. The unicorn seemed to have convinced himself that nopony else would find this passage, though, Starfall's trip being complete uninterrupted and unidirectional.

But once he got back to the castle, what then? Even if Cosmo and Nightmare were still there...which the barrier around the castle suggested they were, there was still the task of finding a way to stop them, preferably without hurting any of them. Starfall was sure they could resist the corrupting influence of the gem's dark magic, if only they could be given a reason to fight it, something to fight for...

Starfall's thoughts were interrupted, however, when he felt a shiver travel down his body, like he had just passed through something. He froze, thinking for a moment that it was a trap Cosmo had laid, ears flattening as he cringed, waiting for something horrific and painful to happen.

But nothing did, and as Starfall glanced around, he realised that the stone tunnel had given way to coarse, roughly chiselled marble...he was inside the castle limits. The shiver he felt must have been from passing through the opening in Cosmo's force field.

Starfall's spirits lifted slightly as he turned back around and rushed on, now more determined than ever. He was back inside the castle...there was still a chance to save Equestria...if he could only figure out what it would take to stop Cosmo and Nightmare Moon.

But the lack of plan did not slow him down. There was no choice...he knew the fate of all of Equestria rested on the next few minutes now. He had to do this: For himself, Canterlot, Equestria, his friends...and for Luna.