The Sanctum
"I can't believe that we got benched like this!," Starlight fumed, as she pacing back and forth.
"Strange didn't want you to get hurt," Trixie said, trying to calm Starlight down.
"But Strange and the others don't know Chrysalis like I do," Starlight replied, "you and I have fought Chrysalis and her swarm before we have knowledge that the team will need."
"All we can do is wait," Trixie stated.
Before Starlight could answer a window-sized portal opened up, showing the Dark Dimension with Doctor Strange and his team being dragged away by changelings and Mindless Ones.
"Starlight, Trixie, we're under attack!" Strange cried, "There is a traitor, he led the changelings and Mindless Ones right to us!"
"What can we do?" Starlight asked.
"Make sure that the Eye of Agamotto doesn't fall into Chrysalis or Dormammu's possession," Strange replied, throwing his amulet through the portal.
Before the window closed Strange looked at his cloak, "you go too," he said.
The cloak seemed reluctant to leave Strange, "Go now!" Strange command, "thats an order!"
The cloak obeyed and flew off of Strange, through the portal.
Shortly after the portal closed.
"Well so much for waiting," Trixie said, munching on an apple.
Upon hearing this, the cloak wrapped itself around Starlight, "Right," Starlight nodded, she placed the Eye of Agamotto around her neck.
In an instant Starlight could see all of time: the past, present and the future, from the Celestials creating the earth to the end of all things.
After that, Trixie grabbed the strange gun-like device from before, "I've a feeling we'll need this," she said.
"Right," Starlight agreed, with that the two dashed out of the Sanctum and into the streets of New York.
As they ran they passed an old man sitting at a table, he looked at them, then confusingly at his beer bottle, then back to them, "I gotta get off this stuff," he said.
The Dark Dimension
"Where is the infinity stone?" Chrysalis asked, the captured Doctor Strange.
"It's safe and far away," Strange replied, "someplace you'll never find it."
"Maybe a little torture will change your mind," Chrysalis smiled, her horn glowing.
"Didn't you hear him?" Johnny blaze interrupted, "it was sent far away from here."
"and we aren't going to talk," Vince nodded,
"Thats right," Elsa agreed, "you'll get nothing out of us, you overgrown cockroach."
"You're not much of a threat without Dormammu backing you up," Strange commented.
"You and your kind are on your own," Wong said, "far from home with no help."
"Is that so?" Chrysalis laughed, "Did you ever wonder how the Evil Eye of Avalon was stolen or how a changeling and Mindless One made it through your Sanctum's magic?"
"No, I don't know," Strange replied.
"The answer is more closer then you realise," Chrysalis smiled, her horn glowed and Mordo was released from his restraints.
"Yes, Strange," Mordo said, as he walked over to join Chrysalis, "it was me, I was the one who led the changelings and Mindless Ones to the Sanctum and to us here."
"Mordo, how? why?" Strange asked, in stunned shock.
"Ever since I saw The Ancient One use the very power we seek to stop," Mordo replied, "I was disgusted that the one I looked up to using the dark powers to stop evil forces."
"You see," Chrysalis continued, "Mordo and I share a common goal."
"What could Chrysalis or Dormammu possibly have offered you, Mordo?" Wong asked.
"Simple," Chrysalis said, "my goal is to raise an army and take revenge on Starlight Glimmer and Equestria, Mordo's goal is to rid the human world of all who using magic to abuse the laws of nature.
"The two of us are one of a kind," Mordo said, as he and Chrysalis smiled at each other.
"I might consider making Mordo my king," Chrysalis replied, blushing at Mordo's comment.
"Please, stop" Johnny interrupted, "I'm getting a cavity."
"If I wasn't tied up," Vince agreed, "I would be losing my lunch, right now."
"Sarcasm will get you no where," Mordo said, giving Vince a quick strike from his weapon, the Staff of the Living Tribunal.
Before Mordo could continue his torture of Vince, a changeling rushed in, "Master, Starlight Glimmer and Trixie are making their way towards us," he said.
Both Mordo and Chrysalis smiled.
"So Starlight Glimmer has the Eye of Agamotto?" Chrysalis said, "this is everything I hoped for."
"You gave an infinity stone to a mere child, Strange?" Mordo laughed, "it would almost insult me if it wasn't so funny."
"Go, bring her to me," Chrysalis ordered.
"And her little magician friend?" Mordo asked.
"Do whatever you want to her," Chrysalis replied, "just bring me Starlight!"
Meanwhile
"Which way now?" Trixie asked.
"I don't know," Starlight answered, "this place is like nothing I've ever seen before."
"Seems the Sorcerer Supreme didn't think to provide a map," Trixie huffed.
"Well, it's not like he had a lot of time," Starlight replied.
"You'd think that he would explain were he was," Trixie retorted, "everything looks the same in this place."
Starlight gave Trixie a look, "Well, it's not like I can just say 'oh, mystic Eye of Agamotto take us to Dr. Strange'"
After Starlight had said the words the Eye of Agamotto activated, the green gem in the centre glowed and a portal opened under the two, transporting them to the outside Dormammu's stronghold.
"I stand corrected," Trixie said.
"Strange and the others must be inside," Starlight noted, "the place will be swarming with changelings and Mindless Ones."
"How are we suppose to know where Strange and the others are being held?" Trixie asked.
Before Starlight could reply, they noticed Mordo motioning at them, "Starlight, Trixie over here," he whispered.
Starlight and Trixie dashed over to him, "Mordo, what happened to the others?" Starlight asked.
"The changelings and Mindless Ones dragged them off," Mordo replied.
"Which way did they go?" Trixie asked.
"They took them to the dungeon," Mordo continued.
"Why didn't they get you?" Starlight inquired, "how did you mange to avoid them?"
"That's not important right now," Mordo insisted, "what matters right now is saving the others."
Starlight, Trixie and Mordo headed into the stronghold of Dormammu.
"This is awfully quiet," Starlight said.
"Yeah, I haven't seen a single changeling or Mindless One anywhere," Trixie nodded.
"It's almost like there waiting for something," Mordo suggested.
As the two ponies proceeded ahead of him, Mordo pulled out his weapon, flicking it from a staff into a wipe.
"Starlight, look out!" Trixie cried, she throw herself at Starlight knocking her out of the way of Mordo's attack.
"I know there was something strange about this," Starlight said, "you were the traitor."
"You really are quiet smart," Mordo smiled, "I can see why Strange took an interest in you."
"What could Chrysalis or Dormammu possibly have offered you, Mordo?" Trixie asked.
"Queen Chrysalis and I simply have alined goals," Mordo replied, "and she has requested I bring you to her."
"You want Starlight," Trixie growled, "then you have to go through me."
"Precisely my intensions," Mordo smiled, his hands lit up with mystical energy and a portal opened behind Trixie.
"Starlight!!" Trixie yelled, as she was sucked into the portal.
"Trixie!!" Starlight cried, as she watched her best friend disappeared into the portal.
"Now without further ado," Mordo continued, "you have an appointment with Chrysalis."
Starlight said nothing, but as Mordo advanced on her.
"The Flames of the Faltine, incinerate him!" Starlight called, with tears in her eyes, she fired a blast of flame at Mordo.
Mordo simply dodged her attack, using another of his personal mystical items the Vaulting Boots of Valtorr, 
After which he processed to knocked Starlight unconscious.