The disappearance of the queen

When I arrived at the castle gates, a guard stopped me aiming his spear.  "Citizen, we don't allow magic past this point," the guard said pointing at the large contraption.  "Wait, I got a message from the princess to meet her immediately," I said.  "Even if you did, you still need to go through the machine," the guard said as a bright light shined behind him.  The princess looked at the guard, "Dismissed,".  "Yes princess," the guard said backing off.  "So did you need the flashy entrance princess," I said.  "No,, but I know how do get other peoples attention," Celestia said chuckling.  "So, why did you summon me hear," I said.  "Lets talk in the castle, we don't want others to know of your true identity," Celestia said deactivating the entrance.  "alright, but I don't know why I need to keep my identity secret, when I already look like a pony," I said walking through the entrance.  As we walked through the castle halls, we came to large metal door.  "So, will the torture start now or later," I said sarcastically.  "No, but  you can do it yourself if you want," Celestia said opening the large door.  "So what did you put inside this metal prison of yours," I said slowly entering the room.  "This room has something to do with your Queens disappearance," Celestia said closing the door.  As I walked down the dark hallway, a small light started to emerge.  "What is that," I said walking towards the destroyed laboratory.  "Your Queen came to destroy all the evidence of her creation," Celestia said levitating a small photo in front of me.  "Why is Chrysalis in this picture, with you and Luna," I said nearly breaking into tears.  "She was never patient zero, she helped create patient zero," Celestia said putting a hoof on my shoulder.  "Then, she's gone to find this patient zero," I said getting myself composed.  "Yeah she wants to destroy him, so that nobody can find out about him," Celestia said levitating a map over to me.  "A map? why," I said confused.  "It shows the last known locations of patient zero," Celestia said.  "Isn't he a changeling, why would he be in big cities in changeling form," I said confused.  "Patient Zero, can't change his color, so he's easy to spot," Celestia said showing me a picture of his face.  "So, I have to find this Changeling, and get Chrysalis back," I said.  "Yep that's the plan," Celestia said.  "Why are you helping me," I said looking at Celestia.  "Because, Twilight wanted to help you," Celestia said pointing at the door.  "Midnight, I never turn down a friendship problem," Twilight said emerging from the doorway.  "Twilight, you didn't need to get involved in all of this," I said.  "No, you are my friend, I want to help out your situation," Twilight said standing her ground.  "Fine, but please keep yourself safe," I said hesitantly.  "thanks, but I think I should pack for this journey," Twilight said.