TVD
2x07 & 2x08

Cassie is still at the Boarding House with her sister but now they have been joined by Jeremy, Elena's younger brother, and Alaric Saltzman, the local vampire hunter who is also the history teacher at the high school, and Bonnie, who Cassie was informed was a witch was on her way with one of her grimoires.

Caroline was the one to answer the door when Bonnie arrived, as the two walked in the witch saw Damon and Alaric and all the weapons laid out on the table, she looks confused "what's going on?"

Jeremy walked past her "we're gonna kill Katherine."

Stefan looks at her "I can explain."

Bonnie looks at him with a raised eyebrow "Please."

Then he repeats what Jeremy said, "We're gonna kill Katherine."

Alaric shows the weapon to everybody "This works with compressed air. The trigger mechanism is up here. I have two of these in different sizes. For you, I recommend this. It fits nicely under the jacket sleeve. You use the trigger when you're ready." Then he fakes killing a vampire and Stefan and Damon look at each other very unamused.

Cassie smirked at him as he shrugged "You wanted me to show you how to kill a vampire."

Cassie grinned with a mischievous look in her eyes knowing that neither Bonnie nor Jeremy have noticed her presence since she's been quiet just listening, "can I have one of those? That looks fun"

Caroline snorted giving her sister a look "you don't need a stake shooter Cassie"

Cassie pouted at her "well that's true... Fire, works just as well like getting struck by lightning."

That made the younger blonde smirk at her sister "or you could hit them really hard with that ax thing of yours and knock you some heads clean off." Cassie laughed grinning at her little sister.

"You know you probably shouldn't be putting these ideas in my head Care-Bear."

Bonnie looked at the older blonde wide-eyed "Cassie?"

The blonde Alien just grinned at the younger girl "hey Bon-Bon."

Bonne smiled at her "when did you get home?"

"A few hours ago... Care made me promise to come to the masquerade party tonight so here I am as promised."

"How do you know about all of this?"

Cassie bit back a smirk "Care filled me in cliff notes version this morning on our way to the grill"

Bonnie chuckles "of course she did, welcome home Cassie."

Damon looked at Cassie "how is blondie here supposed to help if she's just human?"

Cassie narrowed her eyes at him, not liking the tone he was talking about her in "why don't you step outside... you might 'accidentally' get struck by lightning."

Damon narrowed his eyes right back at her "Is that a threat blondie?"

The blonde alien just smirked at him "maybe it is Damon"

He glares at her "who do you think you are to threaten me?"

That made her smirk widen "one I told you I'm Cassie and two I can threaten you if I want to because I'm a Princess bitch and I do what I want."

Hearing what her sister said made Caroline burst out laughing which distracted Cassie from her glaring match with Damon as the older blonde looked at her sister "damn Cassie just throwing that in everybody's face, that you are a literal freaking, Princess."

Bonnie looked at the elder Forbes "wait what? I feel like I'm missing something here."

Cassie looked at her sister "wait you didn't tell them?"

Caroline shook her head "no that's your secret to tell and I didn't want you to get mad at me for telling if you didn't want them to know."

Cassie nodded at her sister then looked at Bonnie with a smile "Okay so basically my dad is Thor... The Norse God of Thunder... He's a Prince, the Prince of Asgard and I'm his daughter making me a literal princess and I love it... that's where I've been the past two years is on Asgard with my dad."

Bonnie looked at the girl stunned "wow."

Caroline laughed looking at her best friend "that pretty much sums up my reaction the first time she told me." After they finish talking Bonnie goes over to talk with Stefan about what's happening tonight.

A little while later after the plans have been made and people are starting to leave Alaric looks at Damon and Stefan "Are you sure you guys don't want me there tonight?"

Stefan is the one that answers him "No, I need you to stay with Elena. I don't want her to know about this."

"Okay. Well, I'll make sure she doesn't leave my sight." Alaric assures him.

Stefan looked at the others "alright if anybody wants to back out, I'll understand."

Damon zeros in on Caroline "yeah. Cold feet speak now. I don't want this going wrong if someone chicken's out. Caroline."

"I won't. Look, she killed me. Fair's fair. As long as there's no werewolf running around."

Damon looked at Cassie "what about you, blondie?"

She smirked at him "I'm in just to make sure that you don't get my sister killed... again."

Damon nods and answers Caroline's previous statement "Oh, I took care of Mason."

Jeremy adds "As long as Tyler doesn't kill anyone, he won't turn."

Stefan looked at the Bennett witch "Bonnie? Are you with us?"

There is a long pause before she answers, "But no one gets hurt."

"Except Katherine. Tonight, Katherine gets a stake through her heart" Damon corrects.

***

Caroline had begged Cassie to not draw attention to herself and to stay back, the young vampire didn't want Katherine to hurt her sister, though Cassie tried to convince her that she could hold her own even against a vampire as old as Katherine. But Caroline would budge on it, so Cassie agreed. Though she didn't promise to stay out of it so she could still do something if she needed to.

Cassie was standing by the punch bowl getting a drink while the others put the plan in motion, so far so good, she didn't need to intervene, but she was keeping an ear out for the sound of trouble. The blonde alien saw Katherine talking to Matt, she knew that the vampire was pretending to be Elena, so she didn't bother listening in on that conversation.

She watched as Stefan walked in looking around for Katherine who had gone upstairs, but kept her distance, she took a seat on one of the little bench things and Katherine or Kitty as Cassie decided to call her walked downstairs and suddenly appeared behind Stefan the two started dancing.

The party was just about as boring as Cassie thought it was going to be, but she promised her sister that she would be there, and as always she kept her promise. A little while later Caroline approached her sister "wanna dance sis?"

Cassie shrugged "sure, it beats just sitting here doing nothing, did it work?"

She nodded "Yep she is trapped in the room with the Salvatores." Cassie nodded at her and the Forbes sisters danced for a while and then Caroline went off to find Matt or something after Cassie told her she was going to head home.

Cassie walked out of the house and got over by the cars when she saw Elena hanging up her phone, so she walked up to her "hey Elena."

The brunette looked at her "Cassie? Oh my god, how long have you been home?"

"Just since this morning... I promised Care that I would come to the party tonight and so here I am." Elena smiled at the older girl and hugged her, Cassie to be nice hugged her back, if she were being honest, she wasn't the biggest fan of Elena. Then everything went black.

Cassie came too with a groan thinking 'it just had to be right after I got back and didn't have enough time to soak up the UV rays from the sun.' Cassie felt like she was tied up and being sat down on a couch or sofa of some sort and then ropes being removed, she opened her eyes finally and looked around, she saw Elena beside her, and she had a cut on her head and was just coming too as well.

Elena blinked a few times and then noticed the person beside her "Cassie?"

Cassie looked at her with a shrug "yeah, I don't know what's going on here Elena."

Elena looked at Trevor, "What do you want?"

But he just shushes her "Shh."

"Please, I'm hurt," Elena told him and he eyed the blood running from the cut.

"I know. Just a taste." He leans down to bite her wound but a woman her name is Rose walks in, and he stops.

"Trevor! Control yourself." Cassie noted that the man's name was Trevor.

"Buzzkill," Trevor tells her as he leaves.

Rose was left alone with Elena and Cassie, she looked at Elena, as she asked a question "what do you want with us?"

Rose looks stunned for a moment looking at Elena "Oh my god, you look just like her."

Cassie rolled her eyes, 'why am I not surprised that this has something to do with Kitty?'

"But I'm not. Please, whatever you," Elena tried to plead with her.

But Rose cuts her off "Be quiet!"

But of course, Elena Gilbert is stubborn and doesn't listen "But I'm not Katherine. My name is Elena Gilbert; you don't have to do this."

Rose rolled her eyes at the doppelgänger, "I know who you are, I said be quiet."

But does Elena listen to her? No, she doesn't she persists "what do you want?"

Rose had enough of Elena's questions and slaps her hard, and the doppelgänger falls back on the couch unconscious "I want you to be quiet."

Rose turned to the blonde alien and Cassie narrowed her eyes "you slap me, and it will be the last thing you ever do lady... now I don't know who the hell you are, but you are going to answer my questions or else"

she raises an eyebrow at her "or else what?"

Cassie just smirked at her "what the hell do you want with me?"

Rose just looked at her "seriously what are you going to do if I don't answer?"

There was a mischievous glint in Cassie's eyes as she held her hand out summoning Stormbreaker to her. Rose looked at her confused "what are you doing?"

Cassie smirked at her gain "you will see in 3,2,1." Stormbreaker smashed through the wall and landed right in Cassie's grasp "now you are going to answer my questions, or I am going to hit you with this," she held Stormbreaker up for the vampire to see "and I can guarantee that will not be pleasant for you... so let's try this again, who are you and what do you want with me?"

The vampire sighed answering Cassie's question "my name is Rose, and I don't want you for anything... you were just collateral because you were with the doppelgänger "

Cassie gave her a look "see now that wasn't so hard now, was it?"