We see Kickin' Hawk beating up a bunch of Black Fang members, all while Roman just watches from a railcar.
Roman: (sighs) "Why does this always happen to me? And, seriously, how'd this guy even find this place?"
Kickin' Hawk: "It's been fun and all. But, I think I'll be showing myself the exit."
Kickin' Hawk then slams on the emblem, turning into a semi-armored Velociraptor, that has black orbs on his feet, a black tail with five blue stripes, and bulky claws on his three fingers that can only open and close. He wears a black cone-like helmet with a protective visor that slides over his face, and a black bodysuit and turtleneck-like shirt with a green stripe on the center. This form being called "XLR8".
XLR8: "Oh yeah, I can totally get behind XRL8."
XLR8 then starts running at immense speed, as Roman stands up, spins his cane, which is called Melodic Cudgel, in his hands, and aims the handle at the high-speed alien. He fires the handle, which doubles as a grappling hook, at a crate, resulting in XLR8 tripping over it, as he crashed into a stack of crates.
XLR8: "Ow...okay, that hurt. Good thing this helmet has a visor."
Roman: "I see you've got some tricks up your sleeve! Let me make this clear: We're not through here yet, whatever the heck you are."
XLR8: "The name's XLR8, and I'm a Kineceleran. And also...boom."
A massive explosion sounds, causing Roman to look up.
Roman: "Oh, what the...Perry, if you and the boys could take care of that? Kinda in the middle of something."
Perry, who is now awake, nods and goes off to investigate the explosion just as another one sounds.
Roman: (annoyed) "WHAT is going on here?!"
A third explosion sounds and multiple Black Fang members come running around the corner, some firing at an unknown enemy. Amber, Erza, Atalanta, Weiss, Blake, Yang, Summer, Rossweisse, Zwei and Oobleck run around the corner, much to Roman's annoyance. XLR8 decides to take this moment to try and escape. He jumps on Roman's shoulders, pulls his hat down over his eyes, and then flees towards his friends.
XLR8: (laughs) "Think fast, loser!"
Roman: (readjusting his hat and glaring after XLR8) "Somebody kill that thing!"
XLR8: "Wow. Now that's just rude!"
Roman and the Black Fang members around him open fire on XLR8, which he dodges and weaves between with ease thanks to his speed.
XLR8: (dodges and weaves between blasts) "Miss me! Miss me! Are you even trying? You're gonna have to move faster then that to hit me! Geez, have any of you ever done this before? Seriously, come on people."
Roman: (angrily turns to the Black Fang member next to him) "Attach this cart and spread the word: We're starting the train."
Black Fang Member: "But we're not finished!"
Roman: (pins the Black Fang member up against the wall with Melodic Cudgel) "Do it or you're finished!"
We then cut to XLR8 fleeing, but screeches to a halt as he realizes he's running towards a group of Black Fang members.
XLR8: "Oops! Wrong turn! Or, is it?"
A huge explosion appears behind the Black Fang members, sending them flying and reveling Yang behind them.
Yang: (notices XLR8) "And what the heck are you supposed to be?"
Erza: "I'm guessing you're a friend of Nick's?"
XLR8: "I go by XLR8 in this form, actually."
Amber: "Oh, so you ARE Nick."
Ruby: "You look so cool!"
XLR8: "Thanks, Strawberry."
Weiss: "Are you okay?"
Nick: (transforms back to normal) "Yeah, I'm fine. But, Torchwick's got all kinds of weapons and robots down there."
Blake: "What?!"
Nick: "Androids, mechs, they're all loaded up on the train cars."
Oobleck: "Ahhhh, that's ridiculous. These tunnels are sealed, the tracks lead to a dead-end."
Roman: (across a speaker system) "Get to your places, we are leaving now!"
The train starts moving towards the tunnels.
Yang: "Well, it sounds like they're going somewhere."
Ruby: "We need backup. Let me call Jaune."
Nick: "You're not gonna get a signal down here."
Ruby's Scroll flashes "Low Signal".
Ruby: "Nick's right, I can't get through!"
Weiss: "So, what do we do?"
Oobleck: "I believe we only have one option..."
Nick: (turns around) "We're stopping that train!"
The scene cuts to the train rushing through a tunnel, loaded with mechs. A Black Fang member standing on the train hears a noise and looks outside the train to see rose petals. He brings out a communication device.
Black Fang Member: "I think they're on the—"
The Black Fang member falls down as Oobleck hits him in the head with his weapon. The shot cuts to Roman in the front of the train as a Black Fang member rushes in.
Black Fang Member: "Boss! They made it on the train!"
Roman: (sighing) "Then grab some cargo and get them off the train!"
The Black Fang member nods and leaves to follow Roman's orders.
Roman: "Man, animals, every one of them."
Roman looks awkwardly at the Black Fang member sitting next to him.
Roman: "Not you though, you're, heh, you're great."
The scene cuts to Team NAAE (Unimaginable), Team RWBY (Ruby), Summer, Rossweise and Oobleck standing on top of the train.
Oobleck: "Hurry, children! We must get to the front and stop this train!"
Weiss: "Err...Professor?"
Oobleck: "Doctor..."
Weiss: (points down at a hatch into the train) "What's that?"
Oobleck: (kneels down to take a look) "That my dear...appears to be a bomb."
Team RWBY (Ruby), Team NAAE (Unimaginable), Summer and Rossweisse all cringe away from the hatch.
Ruby: (points forward on the train) "We've got baddies!"
Dozens of Black Fang members can be seen climbing onto the top of the train.
Oobleck: "Well, I didn't expect them to go—"
The bomb underneath them charges up and starts beeping.
Oobleck: "—easy on us. (stands up) Time to go!"
As the group start running away, Oobleck stops Blake.
Oobleck: "Blake! Detach the caboose! It will kill us all!"
Blake: "On it."
Blake jumps down onto the connectors and gets ready to cut the connection, but as she does, the connection comes loose on its own.
Blake: "Huh? (looking up at Oobleck) It decoupled itself!"
Oobleck: What?!
Yang: "I guess he really doesn't want us on this train."
As Oobleck looks back at the detached cart, it explodes in the tunnel.
Oobleck: "That's not good..."
Ruby: (standing next to another open hatch) "Err, neither is this!"
Blake: "Another bomb?!"
Nick: "They ALL have bombs!"
The bomb under the group charges up and starts beeping as the cart they're on detaches itself, forcing them to run to the next cart.
Yang: "This doesn't make sense!"
The Black Fang members climbing the train can be seen again.
Black Fang Member: "Get the humans!"
Nick: "Three of us are Faunus, just so you know!"
Nick then puts on the Den-O Belt, and transforms into Kamen Rider Den-O Sword Form, much to the shock of the Black Fang Members. Teams RWBY (Ruby) and NAAE (Unimaginable) jump forward to attack the incoming Black Fang members. Oobleck turns around and watches the detached train car explode. Only this time it creates a hole allowing multiple types of Grimm to emerge.
Oobleck: "Oh, dear..."
The horde of Grimm begin advancing quickly toward the runaway train.
Oobleck: "He's leading Grimm to the city!"
Weiss: "What?!"
KR Den-O (SF): "It's the cars! They detach and explode, creating openings for the Grimm to get into the tunnels!"
Blake: "That's insane!"
KR Den-O (SF): "You do remember who we're dealing with right now, right?"
Another train car detaches itself.
Oobleck: "We have to hurry! (to Weiss, Blake, and Yang) You three, go below and try to stop those bombs!"
Ruby: "What about us?"
Oobleck: "We're going to stop this train."
Ruby: "Yeah, I know. Nick said that earlier."
The group moves forward. As the train continues towards it destination, White Fang members start to pilot multiple Atlesian Paladin-290s, and jump to the top of the train. Den-O, Ruby, Amber, Erza, Atalanta, Zwei, Summer, Rossweisse and Oobleck are shown running.
Summer: "Up ahead!"
A Paladin is seen charging towards them.
Rossweisse: "We've got a problem!"
Oobleck takes a sip from his thermos before transforming it into its weapon mode, a small flame burning at its tip. Zwei barks, prompting he's ready for an attack. He jumps and flips in the air, and Oobleck bats him, turning him into a small fireball. The Paladin is seen shooting, only for it to get knocked off the train by the combination attack. The Paladin tumbles on the train tracks, and explodes when it hits a barricade. Another Paladin appears in front of Zwei, its guns aimed at him. Suddenly, multiple fire attacks hit it, and Oobleck swiftly knocks it off the train as well. Down below, Yang, Weiss, and Blake enter the train car.
Yang: "I guess this is what we've trained for."
Weiss reaches into her pouch and gives Blake a magazine filled with Dust vials.
Weiss: "Here, this should help you."
Blake slides the mag into Gambol Shroud, and then the three of them charge forward. Suddenly, the Spider Kamen Riders drop from the ceiling and blocks their path.
Weiss: "Are those Kamen Riders?!"
Blake: "I'm guessing it's the two Kamen Riders Nick and Ruby told us about."
Yang: "You two go on ahead. They're mine."
Blake and Weiss proceed forward. As the Spider Mirror Riders prepare for their attack, Yang fires a round to distract them, allowing Blake and Weiss to continue. Yang steps forward toward her opponents, as the three begin their fight. In the next train car, Blake and Weiss are seen running, and then look at each other when they hear the sound of revving up ahead. A figure is seen dragging a chainsaw along the floor. The camera pans up, revealing the White Fang Lieutenant.
Weiss: "You go on ahead!"
Blake: "Got it!"
The Lieutenant chuckles menacingly as he holds up his chainsaw. The two Huntresses-in-training charge forward, with Blake deflecting an attack as Weiss flips backward. Weiss delivers multiple strikes at the Lieutenant, knocking him down. She then smiles at Blake as she proceeds to the next car. The Lieutenant gets back up, again chuckling menacingly.
White Fang Lieutenant: "Finally, I get to kill a Schnee..."
Weiss holds up Myrtenaster en garde. In the next train car, Blake stops and grits her teeth when she's greeted by a familiar foe.
Roman: "Hello, kitty cat. You miss me? You know, we really gotta stop meeting like this. People are gonna talk..."
Blake charges forward to attack, starting their brief battle. She soon knocks him down, and when he attempts to get back up, Blake steps on his chest and points her sword at his throat.
Roman: (chuckles nervously before his voice gets a dramatic change in tone) "Why are we fighting? I saw you at the rally, we're on the same side and you know it..."
Meanwhile, Weiss is fighting the Lieutenant. Things take a turn for the worst when time suddenly seems to slow down.
White Fang Lieutenant: "C'mere, princess!"
The Lieutenant grabs Weiss' face and slams her into the floor, knocking her unconscious. He then throws her in the air, readying to hit her with his chainsaw...Yang's fight is still going badly and soon ends when the Red Spider Mirror Rider manages to throw her into the ceiling, knocking her unconscious. The two Spider Mirror Riders turns around to approach Yang...We cut back to Roman being held down by Blake, he grunts as she points her blade at his throat.
Roman: "Oh, still feisty. Soooo, what are we gonna do now? You think a little bow on top is gonna make people forget who you were? What you've done...?"
As she grits her teeth at his words, Blake hears the door from the previous train car open behind her. An unconscious Weiss is thrown to the floor, with the Lieutenant emerging from the doorway, holding his chainsaw.
Roman: "So what's it gonna be, Blake?"
She sheaths Gambol Shroud and kicks Roman in the face, knocking him unconscious. Blake goes over to Weiss' aid, and flees immediately before the Lieutenant can reach them. Meanwhile, the two Mirror Riders are seen pulling Advent Cards from within their Advent Belts, and equipping weapons, while approaching the unconscious Yang. They prepare to deal the finishing blow, when suddenly, two masked warriors - one with raven-hair and clad in red and black, while the other is a green Kamen Rider resembling a magical, armored sorceress - come out of nowhere and knock the Mirror Riders back. The mysterious swordswoman slowly draws her sword again - long and crimson red - and holds it up intimidatingly, while the green Kamen Rider holds out a silver gun with a hand on it. The two Spider Mirror Riders, realizing the imminent threat before them, waste no time and disappear in a flash via shattered glass. The swordswoman looks down at the still unconscious Yang, and slashes her sword to the side, opening an eerie red portal. She walks away from Yang and into the portal, as the green Kamen Rider places a hand on her partner's shoulder. At that moment, Yang regains some consciousness and slowly gets back up. As she opens her eyes again, she gets a brief glimpse at her rescuers before the two women disappear. Yang rubs her head, still reeling after just regaining consciousness, before standing up and leaving the scene. Back to Den-O, Ruby, Amber, Erza, Atalanta, Summer, Rossweisse and Oobleck, the Doctor dodges a couple swipes from the Paladin, and then runs to the top of its head, and shoots it in its engine before jumping back down. Ruby twirls Crescent Rose around a few times, and then she, Den-O, Atalanta, Summer and Oobleck fire simultaneously at the Paladin's feet, knocking it off the train. They all then switch positions.
Oobleck: "Nick, Ruby, Amber, Erza, Atalanta! You five go on ahead!"
Ruby: "But-"
Summer: "Don't worry, Ruby. It's time...we teach them a lesson..."
The Doctor, Summer and Rossweisse go to take on two oncoming Paladins. Before they leaves, Ruby notices the saddened Zwei looking up at her. She smiles and motions for him to go join the adults.
Ruby: "Go on."
With that, Zwei expression changes dramatically and barks happily before running off to fight alongside the grown ups. Ruby, Den-O, Amber, Erza and Atalanta hurry to the front of the train. The remaining members of Team RWBY (Ruby) reemerge from the train cars to rejoin their friends. Ruby looks on worriedly as she realizes the train is on a collision course with a thick concrete wall.
Blake: "What do we do?"
Ruby and Weiss smile at each other, and the latter and Amber form an ice shield to protect their teammates, bracing themselves for the impending crash. The train crashes into the wall, the explosion causing the screen to go white. The camera switches to Ruby's first person perspective as she recovers from the collision. She hears the sound of an emergency alarm blaring as her vision comes back with buildings into her view. She turns her head to the lower right and sees Blake and Yang slowly getting back up, her sister coughing as the dust settles. She turns her head again and sees Weiss sitting up against a large piece of debris, who also gives a thumbs up at her team leader signaling she's okay. She also sees Team NAAE (Unimaginable) help each other up. The camera switches back to show Ruby as she sits back up. The team of huntresses then notice, much to their chagrin, that they have returned to the central part of Vale, and multiple civilians in the area notice them among the debris. Ruby hears the sound of low rumbles and growls from behind her. Suddenly, a giant King Taijitu emerges from the hole, and multiple Grimm start pouring into Vale. The civilians scream as they attempt to flee the chaos. The sounds of screams and roars fill the air, and all Team RWBY can do is watch in horror. Cut to a close up on Ruby, her expression changes from worried and scared to angry and determined. The alarm continues to blare as the screen suddenly cuts to black...