The TARDIS evaporated in the Crystal Empire and The Doctor ran out of it looking around at the city. "So, why are we here?" Twilight asked, walking out of the TARDIS being followed by Rose.
"I had a vision of a gray pegasus looking over The Crystal Empire while it burned." The Doctor replied, scanning the crystals with his sonic screwdriver.
"While it burned?" Rose asked. "What do you mean?"
"While it burned, you know, on fire, blowing up, ka-boom. How can I get more specific?" The Doctor said, rolling his eyes. "But who has the strength to blow up an entire city made out of indestructible crystal?"
"Well, the last time I was here, it was to stop an evil unicorn ghost named King Sombra." Twilight explained. "We defeated him using an old relic called the Crystal Heart. My sister in-law Princess Cadence rallied the Crystal Ponies into using their cheerfulness to power the Crystal Heart, defeating King Sombra."
The Doctor turned to face Twilight. "Princess Cadence?" He asked. "Who's she?"
"She's Princess Celestia's niece, and my sister in-law." Twilight replied. "She's married to my brother Shining Armor. You know, I guess that means Princess Celestia is my aunt in-law, or something. Never mind, it's too complicated."
"Where would she be now?" Rose asked.
"Probably in the Crystal Castle Throne Room, performing her royal duties." Twilight said.
"Then that's where we have to go." The Doctor said. "If anything strange has been going on, she'll know."
Twilight showed the way to the Crystal Castle, which wasn't very difficult as it's located in the center of the city. Upon arrival, Rose commented, "It's looks like the Eiffel Tower."
Twilight cocked her head to the side. "What's the Eiffel Tower?" She asked.
"It's a tower in a city called Paris." The Doctor replied.
"I don't know what that is, but okay." Twilight said. They walked into the castle and into the throne room, but what they was not what they expected.
No pony was sitting in the throne, nor anywhere near it. Instead, Shining Armor and several crystal pony guards were standing next to the throne, chatting up a storm.
"But how could she just disappear!?" Shining Armor asked, with a severe tone of anger in his voice.
"I don't know, your highness." A red crystal unicorn replied, stuttering. "I was simply doing my job, giving her the daily work, when she was surrounded by a red explosion. Then she screamed and disappeared. There was nothing I could do."
"That doesn't cut it Firebrand!" Shining Armor shouted, stepping back. "How could you know there was nothing you could do?! Couldn't you perform a spell, or grab her, or..."
"He's a soldier! What do you expect?!" The Doctor shouted. "They don't think about a solution they just shoot things, and then think, and even then, they don't think."
"Who are you, and who let you in?" Shining Armor asked.
"I'm The Doctor, and your sister let me in." The Doctor replied, and walked off to the throne.
"Twily?" Shining Armor asked. "What are you doing here and who are you're friends?"
"Well, this is The Doctor, and this is Rose." Twilight explained. "We met a little bit ago, but they showed that they had abilities unlike any other pony I've ever met."
"So, is he your colt-friend?" Shining Armor asked.
"What?! No! He's just a friend!" Twilight yelled.
"Okay, sorry I'm just in a bad mood." Shining Armor replied. "Something has happened to Cadence."
"What's happened?" Rose asked.
"Some sort of teleportation spell." Shining Armor explained. "And a very talented pony must have conjured it, for it left no magical trace."
"Of course it left no magical trace!" The Doctor exclaimed. and slid down the carpet on the throne.
"What do you mean?" Twilight asked.
The Doctor removed the cushion on the throne and tossed it aside. What was revealed was a flat, metal, circular object with a glowing blue light on it. "A teleport." The Doctor said.
"But, I've seen a teleport before, it doesn't create an explosion." Rose said.
"Excellent question." The Doctor said. "Have any of you noticed that the throne and the area around the throne is a little darker than usual?" The Doctor trotted up to the throne and whipped his hoof across the chair. when he lifted it up a thin layer of black dots was on it. "There's a thin layer of ash on it. It wasn't a spell Firebrand saw, it was just a fancy firework."
"So what did happen to Cadence?" Shining Armor asked.
"When she stepped on her throne a timer was started, so that in an hour she'd teleport. Then a explosion was caused at the same time and she teleported to a different location." The Doctor explained.
"But where did she teleport to?" Twilight asked.
"Only one way to find out." The Doctor said. "Geronimo!" Then he ran towards the teleport.
"DOCTOR DON'T!!!" Rose, and Twilight yelled simultaneously.
Then The Doctor ran onto the teleport, and disappeared.