Someone has been murdering 10 in Canterlot. The humane 6 and Flash are next. Will they discover who it is, before it's too late?

Chapter 4: 8, 9, 10 and the culprit

Late on Friday night, the friends were discussing in hushed voices who'd be doing what.

"Twilight, Flash, Pinkie." whispered Rarity. "Stay outside Sunset's house, find clues. Rainbow and Fluttershy, we're going to search- Fluttershy!"

Fluttershy's lifeless eyes stared up at the clear night sky. "Come on, Dash!"

"Hey, I think it's Sunset," whispered Pinkie. "The figure went into her house."

As if the figure knew someone was talking about them, the figure turned. Pinkie Pie stood frozen to the spot, like a rabbit in headlights. The figure chuckled. "Well well. If it isn't Pinkamena Diane Pie. The girl who has curly pink hair and loves parties and ditched me! You went out of your way to hurt me, now it's my turn to get my revenge. You wanna fight?"

"Yeah, and you will get cupcakes in your face!" cried Pinkie Pie.

"Ha." said the figure. "You can't beat me. I've known you since I was Queen Bee at CHS. And I know all your tricks."

"Sunset, No! We used to work together, what happened to all that?" pleaded Pinkie Pie.

"You betrayed me, every single one of you betrayed me! You hurt me, you ditched me and you forgot all about me! I told you the truth, but did Pinkamena and her precious friends remember me? NO! They did not! And now I'm out for revenge!"

Pinkie had moments left, then her mind went blank.

"Sunset?!" hissed Twilight from inside a bush. "She killed them? Because of what happened before? I dated her then she does that?!"

"I'm sorry, Twilight," said Flash, putting an arm around her. "She'll head for Wallflower. We have to follow her. Text RD and Rarity, now, and tell them to meet at the Sweet Shoppe!"

The 5 remaining members waited by the alley. A green-haired girl was walking on the streets, out of the Sweet Shoppe. Wallflower Blush. Wallflower was eating a donut, thinking about school on Monday, making it up to Sunset Shimmer. Little did she know she would not make it. She turned. She screamed. Then her mind went blank.

Twilight jumped out from their hiding place and placed handcuffs on her hands. Rarity ripped off the mask, as she stepped back.

"Sunset Shimmer! I thought I trusted you!" cried Twilight. "Then you go behind our backs, kill 10 people and now look! My father's coming, he's a policeman. Sunset, we were friends! You saved me in Camp Everfree, was that all fake, Sunny? Answer me!"

"No." replied Sunset. "I wanted to be a better person but the memory stone was my last straw. Twilight, I had to do this. You all betrayed me."

"Why didn't you tell anyone?" begged Twilight. "Why?"

"I had to!" cried Sunset. "I had no choice! You betrayed me! You heard me yell at Pie!"

"Why didn't you speak to Celestia or Luna or ME?" yelled Twilight. "Sunset, this is my fault. Our fault. I will tell my father that Dash, Rare and I are guilty. We caused this. I'm sorry Sunny."

"And me," said Flash. "I ignored you. You needed help, yet I did nothing to help you at all. We all deserve to go."

Twilight's father's car pulled up. "Dad, Sunset is guilty of the unspeakable crimes, but the 4 of us caused it. We abandoned Sunset when she needed help the most and she had no choice. Dad, take us as well. We deserve it."

"Twilight, no!" cried Sunset. "It isn't your fault. You should be free. No, take me and Dash. Dash has done unspeakable things as well. She's... she was a middle school bully and by accident, killed Score by punching him really hard."

"It's true," said Rainbow Dash. "Don't take Rarity, Twilight or Flash. Take me and Sunset. We deserve it. And I don't think Sunset could have ever killed me because... because when you 2 split up, Twi, Sunny and I were actually in a relationship and you found out. I would rather spend my whole life with someone I love, rather spend it on my own."

"Fine. Dash and Shimmer it is," said Night Light. "Twilight, I'm proud of you for alerting me."