The Rosewood Mall parking lot was packed. The chatter of excited teenagers filled the air as spotlights beamed into the dark sky, announcing the biggest event of the night: Big Time Rush live in Rosewood.

Inside the mall's grand atrium, a temporary stage was set up with flashing lights and a massive screen displaying "BTR" in bold letters. The crowd was electric—well, most of the crowd.

At the back, arms crossed, stood Aria Montgomery, Hanna Marin, Emily Fields, Spencer Hastings, Alison DiLaurentis, and Mona Vanderwaal. Their expressions ranged from bored to irritated.

"Tell me why we're even here?" Spencer hissed, flipping her perfectly straightened hair over her shoulder.

"Because Alison forced us," Hanna groaned, blowing a bubble with her gum before popping it aggressively.

Alison smirked. "Well, duh. We have to keep an eye on them. New people. New threats."

"Yeah, because four dorky dudes singing bubblegum pop are definitely part of 'A's master plan," Emily deadpanned.

Aria sighed. "And I ditched Ezra for this. I swear, if I miss out on some deep, brooding conversation about 18th-century literature because of a boy band—"

"They're not even a real band," Mona interjected, rolling her eyes. "They were created by Nickelodeon."

"Ugh," Spencer muttered, rubbing her temples. "Why do they all have the same haircut? The swoop thing? Are they in a cult?"

"Yeah, a cult of bad music," Hanna said.

The stage lights dimmed, and suddenly, loud screaming erupted as four silhouettes strutted onto the stage.

"ROSEWOOD MALL! ARE YOU READY TO RUSH?!"

Kendall Knight's voice rang through the speakers as a guitar riff started playing. The crowd went feral.

James Diamond grabbed the mic. "Let's hear you scream!"

Carlos Garcia backflipped onto the stage because he couldn't enter a room without doing unnecessary acrobatics.

Logan Mitchell adjusted his leather jacket, smirking. "Alright, Rosewood, we're about to take you worldwide."

Cue the music.

The girls groaned in unison.

The opening beats of "Worldwide" echoed through the mall, and the crowd swayed, totally entranced.

Alison, however, smirked devilishly. "Girls, watch and learn."

Mid-song, as Kendall and James leaned in dramatically to harmonize, Alison cupped her hands around her mouth and booed.

Loudly.

"BOOOOO!"

Spencer choked back a laugh.

Hanna caught on immediately. "OH NO, THEY SUCK SO BAD!" she fake-gasped, earning glares from nearby fans.

"IT'S GIVING LOCAL TALENT SHOW ENERGY," Mona shouted, just to be obnoxious.

Logan faltered mid-lyric, but he quickly recovered.

Emily and Aria, still skeptical about this plan, remained silent. That is, until Alison elbowed Emily.

Emily sighed, rolling her eyes. "This is so embarrassing."

"Not as embarrassing as their dance moves," Spencer quipped, watching James attempt to moonwalk.

"Boo!" Aria finally chimed in, half-heartedly. She just wanted to go home.

The crowd around them turned.

A girl with braces wearing a "MRS. KENDALL KNIGHT" shirt turned around. "Um, EXCUSE ME? You guys are just haters!"

"Okay, Brittany," Hanna snarked. "You're, like, 12. Calm down."

The fans turned on them. Death glares. A couple of girls whispered.

"They're just mad because they're irrelevant," one fan muttered.

"Uh, excuse you—" Spencer started, but before she could pop off, Kendall spoke into the mic.

"Alright, Rosewood, let's hear it for all the supportive people tonight!"

The crowd cheered, making the Liars seethe.

James smirked, catching onto the drama. "And for the haters in the back—"

Carlos took the opportunity to be extra. "Womp-womp," he said into the mic, mimicking a sad trombone sound.

Mona's jaw dropped. "Did he just womp-womp us?!"

The band continued as if nothing happened, but the Liars were plotting.

By the time "Boyfriend" started, Aria had had enough. "Screw this, I need coffee," she muttered, storming off.

"Agreed," Spencer said, following.

Alison watched them leave. "Oh, don't worry, we'll deal with them later."

The post-concert chaos was worse than the concert itself.

BTR, sweaty and high on their own egos, walked through the mall's staff exit, signing autographs and posing for pictures.

Then they saw them.

The Liars, standing directly in their path. Arms crossed. Faces stone cold.

Kendall smirked. "Aw, if it isn't our biggest fans."

Hanna scoffed. "Yeah, no. You guys were awful."

James gasped dramatically. "You wound me!"

Logan snorted. "Oh, I love this. Insult us more."

Emily squinted at them. "You think this is funny?"

Carlos nodded. "I mean… yeah."

"You guys are so obsessed with us," James taunted. "Did you boo us just to get our attention?"

"Not even in your dreams," Spencer snapped.

"But Spencer," Kendall smirked, "you love me. I can feel it."

Spencer's face twisted in horror. "Excuse me?!"

"Oh, definitely," James added, flipping his hair. "We're your biggest secret crushes. It's okay, we get that a lot."

Mona narrowed her eyes. "I will end you."

Kendall smirked. "Ooh, I'm scared."

Mona, unfazed, reached into her purse and pulled out a glittery pink taser.

Carlos's eyes bulged. "AH—NOPE. NOPE, NOPE, NOPE."

James yelled, running behind Logan. "WHY DO YOU HAVE A TASER?!"

Mona shrugged. "Why don't you?"

Aria crossed her arms. "You think this is funny? That we booed you? That we don't like you?"

Kendall raised an eyebrow. "Yeah, kinda."

James sighed dramatically. "If it makes you feel better, I was offended."

"Good," Spencer deadpanned.

Carlos grinned. "Do you guys wanna hug it out?"

Emily pointed a finger at him. "Touch me and I will drop you."

Logan, realizing this had escalated, cleared his throat. "Well, this has been super fun, but I think we have a plane to catch. So…"

Kendall threw up a peace sign. "Stay pressed, ladies."

James smirked. "We're famous, after all."

And with that, BTR left.

Silence.

Pure, boiling rage.

Hanna exhaled. "Did they just—"

Spencer cut her off. "Did they just insult us and WALK AWAY?!"

Mona's eye twitched. "We should kill them."

Emily rubbed her temples. "Mona, no murder."

Alison nodded. "No murder… yet."

Hanna cracked her knuckles. "We have resources."

Spencer smirked. "We're very good at ruining people's lives."

Aria, still bitter about ditching Ezra for this, nodded solemnly. "They have no idea who they just messed with."

Alison's grin was pure evil. "Oh, but they will."

And just like that, the beef was on.

Big Time Rush vs. The Pretty Little Liars.

No one was safe.