"Is this really goodbye?" said Derpy as tears streamed down her face as she stepped out of the TARDIS and onto the streets of Ponyville. Derpy looked around and saw that everything was the same as the day she left. Nothing had changed, Applejack was still selling apples with her sister and the same couple were still eating their sundae at Sugarcube Corner. It had seemed like days, month, or even years to her, but to them nothing. As the ponies passed by, Derpy sniffed and tried to fight back her tears as if she knew her adventure was coming to an end.
"Why does everything look so normal?" asked Derpy giving the Doctor a strange look in confusion, "It looks like nothing happened. Its just boring old Ponyville"
"Because, I brought you back yo boring old Ponyville. I brought you back to Ponyville where nothing change and nothing will change." replied the Doctor, "I took you back home."
"Why did you take me back?" asked Derpy in a voice filled with anger, "I didn't want to go back. Why did you take me back?"
"It's getting dangerous, really dangerous. I don't want get you hurt and take Dinky's mother away." explained the Doctor, "You have to go back to your life before you met me."
"Do I really have to go?" asked Derpy as tears were already streaming down her face, "I don't want to go, why can't I stay? Tell me, why can't I stay?"
"It is, and I'm sorry. So very sorry." replied the Doctor as he departed out of the TARDIS, "I wish you could stay, but I can't risk you getting hurt."
"I won't get hurt, I'll be careful!" shouted Derpy as the tears on her face streamed at a faster pace, "How can I got back, after the things I've seen. The things I've done, it will never be the same."
"They always say that. Every single one of them. They never do get hut, but only lost or taken away from me, but now I'm in a whole different new world. I can start fresh and never have to deal with all the pain it caused me." sighed the Doctor "Every time I lost a companion became a little more mad. I don't want to be mad, nopony will talk to the madpony over there that scares everypony. I can't let happen to you, I can never bring myself to it. That's why you have to go and that's why you can't stay."
"I won't get hurt, you know that. I may be a kultz, but when I put my mind to it I mean it." cried Derpy, "I can't go. I can never go back to my old life and you know that."
"You have to do it, its the only way that I know your safe." replied the Doctor, "It is the only way I know for a fact that you are safe."
"But I-"
"Derpy!" the Doctor interpreted as his voice cracked trying not to cry, "I'm sorry but its for the best. Your a mother and I don't want to take that from Dinky."
"Your different, I just don't want that risk anymore." replied the Doctor in a sweet soft voice, "I already lost so many, I don't want to loose anymore."
"You won't lose me, you know that." said Derpy, "I'll never be lost and I will always be by your side no matter what. I'll be careful, you know that."
"I know, but I can't risk that. Goodbye Derpy Hooves, and be as brilliant as ever." said the Doctor as he stepped closer towards Derpy, "Take this as a reminder as me."
With that, the Doctor had kissed her, Derpy had closed her eyes and kissed him back. She had wrapped her hooves around him and he had done the same. After a while, he pulled away and went back into the TARDIS.
"That is why you can't stay." replied the Doctor, "I will never age while you will. I'll remain young and just only change my face, while you will grow old. I can never bring myself to let that happen."
"I-I-I understand." stuttered Derpy as she cried softly, "I'll miss you."
"I'll miss you too. Tell Dinky I'll miss her and be as brilliant as ever. No matter what, don't let any other pony tell you different. Goodbye Derpy, I'll never forget you." said the Doctor as he closed the big blue box's doors and to be never seen by her again.
As the TARDIS slowly vanished, she couldn't take it anymore. Tears were streaming like waterfalls as Derpy cried, "I will never forget you either. You were never like the other ponies. You didn't make fun of me. You just smiled and held out your hoof as I followed you off in your big blue box. Something new and something old you said it was." Derpy said as she tried to laugh but it had hurt to much, "You said you stole it, but I doubt that's true."
Derpy sighed and hung her head low and walked slowly back to her cottage, "Goodbye Doctor. I will be forever and ever be your assistant, no matter what. Until the day when time ever does end,I'll remember you and when Dinky is older, I'll make sure to tell her stories of the madpony and big blue box of mysteries and adventures."