Disclaimer: I don't own or claim to own RWBY or the Aerosmith's song. Both of them belong to their respective owners.
It was the time of the annual Beacon celebratory dance and everyone at Beacon Academy was having a mighty good time. Ruby was bobbing her head right and left in tune with the music of the performing band and Nora was attacking the buffet like a starving Ursa. Not that the Grimm were capable of feeling hunger or anything other than hate really, but you've got the idea. Even Weiss was visibly having fun, dancing gently next to Neptune Vasilias under the artificial light produced by the flickering dust projectors.
And then a sudden gunshot shatters the silence like the engaged scream of Yang when someone messes with her hair products.
"Jaune's got a gun."
A male voice rises from somewhere in the crowd, but curiously enough that person isn't yelling in surprise or fear. Oh no, it is actually singing!
"Jaune's got a gun."
Another voice repeats following the first man's example and the sea of people parts to show a bleeding Cardin dying on the flood and the young blond knight standing above the downed team leader with Blake's Gambol Shroud in his hand and bitter tears running down from his eyes.
Weiss grimaces as she runs to press a delicate palm against the frozen Mystralian champion's shoulder.
"Her whole world's come undone."
Yang mumbles-sings as she spares a glance at poor Pyrrha. Was that singing thing Jaune's semblance perhaps? Yang wanted to swing her fists for as long as she could and Ruby wanted to be a hero and always be the first one to arrive in an emergency and so her innate powers reflected those desires. So was that bizarre phenomenon occurring right now Jaune's semblance perhaps? Had the blond knight's only desire really been to meet people that enjoyed his music and had fun while singing his terrible songs?
"He is lookin' straight at Sun"
Somebody sings and Blake's eyes widen as the cat faunus whips around her head to stare at the blond boy accusingly, her eyes suspiciously darting between the monkey faunus and her pistol clenched in Jaune's hand. Sun looks at her with fear and guilt written clearly on his face.
"What did Cardin do?"
Pyrrha finally sings as she drunkenly approaches her secret crush. She needs to know. She needs to understand him and his actions. Maybe then she can still forgive him. But Jaune refuses to answer to her, his ashen face silently staring at Cardin's lifeless body. And so Pyrrha is forced to attempt finding the answer once more. Her broken tune matching her pained accelerating heartbeat.
"What did he put you through?"
The young knight finally snaps out of it, spares a teary apologetic look at his former partner and friend and then makes a run for it, shoving students and visitors out of his way. Ruby collapses on the floor crying for the loss of her first friend.
….
The cast is currently gathered at Beacon's cafeteria. They stab and slash at their food with dull weapons made of stainless steel and cheap plastic, but they don't seem too fond of finishing their untouched meals. Ruby is still in shock, lying down on the infirmary. Pyrrha is currently missing. Cardin's funeral had ended a few hours ago and not even his own team had bothered attending it. Poor bastard.
"They said when Jaune was arrested they found him hurling chucks in a bullhead bay."
Yang offers, the tone of her rough scratchy voice still following a nonexistent musical beat. The blond knight's semblance has yet to stop affecting the students.
"But man, he had it comin."
Yang sings when none of her friends bother keeping alive the conversation. Nobody seems to want to talk about the former knight's fate or the bully's death and that really annoys her.
"Now that Jaune's got a gun, he ain't never gonna be the same."
Nora lowly whispers, her words still dancing to the infernal missing tune and the others just nod, not bothering to correct the hammer wielder when she decides to point out that the possession of a handgun changed Jaune instead of.. you know, murdering Cardin in cold blood.
"Jaune's got a gun."
Mumbles Weiss, still in shock from the scene she had previously witnessed.
"Jaune's got a gun."
She breathes out again as if that would actually change something.
"His Beacon's days are done."
Grunts Blake the weapon of which is still currently unaccounted for. Another gunshot can suddenly be heard from inside the academy's grounds.
"Ren grab the pancakes and run."
Yell-sings the orange-haired hammer wielder of team JNPR and she almost collides with the little reaper of team RWBY when the red themed girl suddenly appears in front of her in an explosion of scarlet rose petals, her silver eyes still leaking surprised and confused tears. The five friends freeze as another gunshot rings inside the academy, this one fairly closer to their current position. The little reaper's clenched fists start trembling and Yang can already guess the reason behind it.
"Ruby tell me now it's untrue."
The blonde brawler sings in remorse and a lot more people start singing obscenities when two Atlas soldiers suddenly march inside the room and start apprehending Blake.
"What did the Blakey do?"
Questions Nora even as the cat faunus seems to quietly comply with their wishes without a single word of protest. A gunshot rings inside the silent cafeteria and Nora starts singing at the top of her lungs as everything turns into chaos.
"Run away, run away from the pain."
An Atlas soldier suddenly drops dead as a bloodstained knight makes his appearance.
"Run away, run away from the pain!"
The other guard unhands Blake and attempts to reach for his rifle, but two crimson holes instantly splatter against his chest forcing the man to collapse on the dusty floor of the cafeteria. The smoking barrel of the gun is then aimed at the frozen students and particularly the singing Nora.
Jaune's eyes are dull and lifeless, his bloodstained face devoid of any visible emotion or remorseful tears after killing those two men. Nora attempts to warn her friends one last time as her voice rises in a hysterical pitch that resembles a mad electric guitar solo.
"Run away, run away, RUN, RUN AWAY!"
A single gunshot echoes inside the cafeteria and Nora's song is instantly silenced. The solo turns into a quintet with Lie Ren singing the loudest.
….
Meanwhile Glynda Goodwitch and headmaster Ozpin are running towards the sound of the gunshots.
"Mr Arc's got a gun."
Glynda sings as her high heels clank against the floor of the empty hallway.
"Mr Arc's got a gun."
Ozpin calmly agrees as they witness the first signs of the bloody massacre.