After gathering all the information she needed, Celestia led Colgate, Lyra, Megan and the Ponyland ponies into the Everfree Forest and towards the portal. They could hear the growling and howling of the timberwolves yet they knew not to approach the group. They knew not to approach Celestia as unlike with the energy of regular unicorns or other methods of destruction, that they could not be reborn after suffering a blast of energy from her.
Several hours pass and they finally reach the darkest part of the forest, the place where the waterfall lies. Celestia looked at those from Ponyland, pointed her wing towards it and said, "Well, the time has come for all of you to return to your homeland."
Majesty asked, "So now will you force Colgate to remove this horn cap?"
Celestia replied, "Not yet, not until right before I cast a necessary spell before you go home."
Megan asked, "A spell? You are going to cast a spell on us before we go back through the portal?"
Celestia replied, "Yes, I am. I must cast a spell to erase the memories of this place, all of us and any other events that have taken place here. If those are allowed to remain, you may reveal information that could alter the future from your end and cause this timeline to never arrive."
Colgate added, "Long story short, she can not allow you to prevent us from ever existing."
This caused them to sigh in frustration as they did not like the idea of having part of their lives wiped out from their memories but it was Megan who was the most opposed to it. She asked, "Must you do that to all of us. Given that I live across the rainbow bridge on earth, can't you let me keep my memories of this place?"
Celestia replied, "No I can not. The risks are simply too high and the fact that you will be passing through Ponyland on your way home, you may say something and endanger altering the future from that point."
To make things easier Celestia teleported everyone into the cave where they saw the portal. Celestia knew that for the memory erasing spell to truly work, that they would have to be facing the portal, facing away from her, Colgate and Lyra. She said, "Alright, I need you all to face the portal." She looked at Colgate and ordered, "Colgate, now you must remove that horn cap."
Colgate sighed, "Oh alright" as she reluctantly removed the cap.
Majesty grunted, "Well it's about time. Ponyland would have been in grave danger had she not removed that cap, it could have caused it's demise sooner and ruined that continuum you are so concerned about which would have caused you to never come to be."
Celestia replied, "That is right. Now all of you must face the portal."
They all faced the portal as Celestia held them in her aura. She spoke,
"While having memories can be great,
In some instances they can create hate.
When this is the case,
In the mind it has no place.
For now the events of recent must be put away,
As we can not allow the fabric of time to fray."
As soon as she finished the spell she levitated the eight through the portal. She yelled, "Colgate, Lyra, look away. Destroying this portal will create a blinding flash of light."
The two turned their backs to Celestia as she fired energy at the portal. She began to glow brighter than a thousand suns as she began to drain the portal's energy. As it became weaker it began to shine brighter and brighter until it disappeared entirely. On both sides a huge explosion rocked the earth. On the Equestrian side, it threw Celestia, Lyra and Colgate out past the waterfall into the river that it feeds. On the Ponyland side it threw Megan and her friends out of the cave and as it had been before, a rock slide caused the side of the hill to collapse, blocking the cave's entrance. While nopony on either side was injured, one thing was for sure. The portal between Ponyland and Equestria was gone forever.
As they peaked their heads above the water, Colgate asked, "Your Majesty, I'm curious, what caused that portal to form in the first place."
Celestia replied, "You know, I'm not entirely sure. If they remember anything at all about the portal on the other side, I'm sure Majesty would blame Tirek or some other evil force. I think it simply existed as some sort of strange anomaly."
Lyra's ears perked up and asked, "Do you think there are any other portals to Ponyland?"
Celestia glared at her and replied, "I doubt it."
Colgate growled, "And even if there are, I want no part of it. I will not search for it, I will avoid it like the plague and I do not want you going looking for it either. Doing so could destroy us."
Lyra asked, "What if it were to lead to the future from here, a future after Equestria?"
Celestia gave her the deepest scowl she had ever given anypony in her life and growled, "Lyra Heartstrings, that will not be the case because my sister nor myself will allow that to happen. As long as we are alive, which will be forever, Equestria will not fall."
Colgate asked, "So what is going to happen now?"
Celestia replied, "Well I am going to cast a spell around the old castle that will put a force field around it that only Luna, Cadence, Twilight and her friends and myself can penetrate. Nopony else will be able to."
Lyra asked, "Why?"
Celestia replied, "Because Colgate has proven that access to the information in there can not just be given to anypony....." Celestia paused for a moment and continued, "Perhaps instead of putting a force field around the castle, I should finally relocate those books from the old castle to the royal library in Canterlot."
Lyra asked, "But then won't ponies be able to go in and read them?"
Celestia replied, "No they would not because I plan on placing them in an area that nopony except for my sister and myself will have access to."
Colgate asked, "Not even Cadence or Twilight?"
Celestia replied, "No. After this I have decided that only natural born Alicorns can safely have access to all this information." She pointed her wing back towards Ponyville and continued, "Let's get going. I am hungry and I'm sure you two are as well."
While Celestia would never tell anypony else about this, there were several other portals that connected Equestria and Ponyland, portals that she decided must be destroyed. Over the next two weeks she headed to these portals and destroyed them, ensuring that Equestria could never be destroyed before it could even come into existence.
In Ponyland Megan and the ponies hit the ground hard when the explosion from the destruction of the portal threw them out of the cave. As the hill began to collapse Megan yelled, "Run! The hill is collapsing!"
They quickly got up and ran away from the collapsing hillside. While they knew what was going on, they had no clue as to why they were by that hill to start with. Posey asked, "Uhm, I'm not sure about any of you but why are we here with that hill collapsing?"
They all shrugged their shoulders as Twilight replied, "I'm not sure Posey. I don't even know why we were here to start with."
Besides her erasing their memories of Equestria and all that happened there, Celestia also erased all memories of Colgate and Lyra from their minds entirely. Megan said, "Well I don't know why we are here but think we should get going?"
They all nodded and headed back to Dream Castle where they were met by the guards. They bowed to Majesty and asked, "My Queen, it is so good to see that you and your friends are alive. We were worried about you."
Majesty asked, "Why would you be worried about me? It's not like I went on some dangerous journey."
The guard was puzzled by her statement. He asked, "But Majesty, you and Megan were kidnapped by those large eyed ponies! They took you off to who knows where!"
All eight of them burst into laughter. Majesty laughed, "Large eyed ponies? That is a good one."
Twilight added, "Come on, you know there aren't any large eyed ponies."
The other guard asked, "You don't remember that?"
A third guard asked, "How could you not remember that? Did they put some sort of spell on you to make you forget what happened to you?"
Majesty continued to laugh, "You know, perhaps you three have been working too hard and need some rest and relaxation. Tell you what, take a few days off. I don't want my guards being delusional and being unable to protect Dream Castle."
The three nodded and departed for home. Megan asked Majesty, "Why do you think they seemed so adamant that large eyed ponies actually exist and even if they did, how would they be able to take us to their world?"
Majesty replied, "Like I said, I think they are simply overworked and needed some time off." She paused for a minute and continued, "Megan, you've been over here for quite a while now. Don't you think you better get home? Don't you think your family might be worried about you?"
Megan replied, "Yeah, I probably better get home."
While the ponies were certain that the guards' claims of large eyed ponies were nothing but delusional nonsense, Megan, despite agreeing that they did not exist, couldn't help but wonder if their claims were legitimate. She reached the rainbow bridge and crossed over back to earth. Suddenly it hit her. She gasped, "The guards were right! Those large eyed ponies do exist, Equestria exists, that portal was real, that huge winged unicorn was real!"
While Megan wanted to reveal all of this to Majesty and the other ponies the next time she went to Ponyland, she decided against it. She did not want Majesty to react to her the way she reacted to the guards and while she would never admit it, she did not want to alter things that would stretch well beyond her lifetime and prevent an entirely new world to come into existence.