Spike went to the mailbox to grab the mail. He went through all of it like it probably wouldn't matter.

"Let's see." Spike said going through all the mail. "Bill from the restaurant, Restraining Order for me from Caramel, Invitation to Princess Celestia's and Princess Luna's birthday, and another Restraining Order from Berry Punch also for me." And then he just remembered one of the letters. He then switched the mail back to that one and stared in awe, but then quickly went in the library to tell Twilight. "TWILIGHT?!"

Twilight was busy reading, but was then nearly hanging on the ceiling after the way Spike called to her. "Spike!" She then used her wings to gently land on the floor. "You know how I don't like it when I get surprised like that, but alright you have my attention. What is it?"

Spike pulled out the mail. "Look what came in the mail."

Twilight used her magic to levitate the mail he was showing her. "Another restraining order, Spike I told that you shouldn't constantly beg for gems."

"Hey they're just not as generous when it comes to giving gems like Rarity is. And that's not what I wanted to show." Spike then grabbed the mail from Twilight's magic. He then flipped through and found the invitation. "I was talking about this."

Twilight then looked at the invitation and just like Spike she was staring in awe. "An invitation to the princess's birthday."

"I heard that besides the Grand Galloping Gala, this is the greatest party in all of Equestria." Spike said placing the mail on the nearest desk.

Just then they heard many knockings on the door as if some pony is about to knock down the door. And just to Twilight's luck the door got knocked down. "TWILIGHT?!" She saw that all her friends were the ones that knocked the door down.

"Again, seriously." Twilight said gently coming down to the ground.

"Sorry darling, but we just couldn't wait any longer." Rarity said.

"Alright then what is it?" Twilight said using her magic to fix the door.

"We just got invited to the birthday party of the two princess's." Rainbow Dash said showing the invitation. "Out of all the birthdays in Equestria, today we get to go to the princess's."

"I know isn't it great?" Twilight said joining every pony in amazement."

"Darn tooting it is." Applejack said.

"It certainly is going to be the best ever." Pinkie then grabbed her party cannon. "And I guaranteed that this party is going to be-" She then fired the party cannon at the same time as she jumped in the air, spreading confetti and streamers everywhere. "FUN!"

Just then Spike burped a letter from Princess Celestia and started reading it. "Pinkie this is for you."

Pinkie Pie grabbed and read out loud.

Dear Pinkie Pie

I want this party to be the best, especially for Princess Luna and I plan on hiring the best party planners in Equestria. So it is with great pleasure that I would like to make you one of the two party planners.

Yours Truly
Princess Celestia

"That's great Pinkie." Twilight said. "I didn't know that Princess Celestia would want you to help plan the party."

"As Celestia as my witness I will make this the best party she and Luna has ever seen." Pinkie said making the gestures of a Pinkie Promise.

"Wait a second, didn't she say that you were one of the two party planners?" Fluttershy said in her small voice.

Twilight then looked at the letter and saw that there was more written. "Look there something else written on here." Pinkie then continued reading.

P.S.
It has come to my attention that one of the party planners I asked to help seems to know you.

It took the a while to think about who it was and then they all seemed to be thinking of the same pony. "You think it might be?" Pinkie broke the silence.

"Only one way to find out." Twilight said. "Let's go to Canterlot and get this party started." After that they all left for Canterlot.

On the way to the train station Pinkie was the one that got mostly excited about this since the last party she planned. It wasn't really long since Rainbow Dash's birthday and anniversary of the day she first came to Ponyville. It also was the first day that she planned a party with another great party planner that was as good as her. Cheese Sandwich!

"I sure do hope that it actually turns out to be Cheese Sandwich." Pinkie Pie said.

"Yeah, it takes one of you to make an awesome party and it takes both of you to make the most epic party ever." Rainbow Dash said.

"That we all agree on." Twilight said. "I'm just glad that Princess Celestia wants you to plan the party Pinkie Pie."

"There's one thing I find weird." Spike said making every pony look at him. "Luna is Celestia's younger sister yet this party is for both of them."

"Princess Luna might be years younger than Celestia, but she was born on the same date as she was." Twilight said hoping that, that would answer the question.

"Wait girls I just thought of something." Fluttershy said getting every ponies attention. "When we thought the Grand Galloping Gala would be one of the best parties we were wrong. What if this party turns out to be just like that?"

"Then it would be a reason for me and hopefully Cheese Sandwich to be there." Pinkie said. "I mean what kind of party would it be if there was no dancing, party music, or ponies that want to party? I'll tell you what kind of party that would be. It would be a boring party."

"Maybe this is the reason why she asked you to plan the party." Applejack said.

Just then the train boarding for Canterlot came and then they all headed over to Canterlot once the train left the Ponyville Train Station.

Author's Note

Let the party begin!