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There. Done. Now with the valve gone, the speed of the train will be uncontrollable and-
“You disgusting pirate! I’ve called the officials, they’ll be coming to get you soon, you-”
Katsuki throws his wrench behind him, and it hits squarely on the conductor’s face, making him finally shut up. Fucking chatterbox. Who is he to tell him what to do?
He could fuck around with some other parts too to really mess up the train, but the constantly accelerating train should cause enough chaos for Katsuki to carry out his heist without any problems.
Besides, this particular treasure is important. Too important to waste more time fiddling around the boiler room.
He crawls out the window and up the roof of the train. Damnit, the wind is a real fucking pain. He doesn’t let it bother him though. The steel clangs with every running step he takes as he looks for the goods wagons. Distantly, he can hear the passengers' screams. Good.
The goods wagons are at the very back, as per fucking usual. Which one did Aizawa say it was again? The third one? Whatever. He climbs down onto the nearest gangway connection and takes out his handy tension wrench. Soon, he picks the lock open and rushes in, shutting the door behind him.
“Oi! Where are you!” He calls, watching for any movement amongst the sacks or any particularly odd notings on the boxes.
Fragile, fragile, fragile… Holy shit, everything’s fucking fragile. How heavy was that fucker again? Like a hundred kilograms? God, these words are so fucking small…
Right then, Katsuki notices a low, strained melody coming from the corner of the wagon, almost like a shadow. He immediately heads towards it, uncovers the sack and yep, he’s found him.
Except… “Shit, you’re so fucking dry. Do those fuckers not at least know how to take care of the sirens they catch? Jeez, wait, wait…”
Thankfully, he’d brought a bottle of water. It was for his own thirst, but whatever. He’s not the one that needs it right now.
He pours it haphazardly across the siren’s body and he lets out a gasp in relief. He looks significantly less pale and his scales are a little shinier.
He smiles. “You came.”
Katsuki scoffs, but can’t hide his own smile. “You called, Shouto. Now let’s get the fuck out of here, holy shit.”
Shouto yelps shrilly when Katsuki stuffs him back into the sack. He turns to shush him, but he already knows the attendants have heard. They’ve got to leave, fast.
He grabs the sack and slings it across his back then bolts out the other gangway connection, jamming the tension wrench into the lock, before throwing the sack onto the roof (it lands with a thud and an “uuf”) and climbing up.
From up here, he can see there are sparks along the rails and the only reason the train hasn’t completely derailed is because the back part that already has is being held up by the tunnel they’re in.
Also, tunnel. No easy escape route. Damnit, this tunnel better end soon.
He doesn’t have any choice but to sit and wait. In the shadows he can see the outlines of an attendant on the gangway connection he came from. They push the door open frantically. Ah, shit, Katsuki forgot to cover up his tracks. He hopes the wet, empty space in the corner isn’t too obvious.
Either way, they seriously need to get out of here. The attendant might not be brave enough to climb up and deal with him properly, but if they have any long range weapon, he’s still screwed. Plus, the longer they stay on this train, the higher the chance of someone with actual balls daring to deal with him. Argh, think, think, what kind of back-up plan can he have?
“Katsuki? Are we out?” The sack moves behind him. A head pops out, heterochromic eyes glowing in the dark.
“Not yet. This fucking tunnel is going on forever. Rest up, I don’t know when next I can get you your water.”
Shouto’s brows furrow, but nods and dips back into the sack.
“Hey!” A voice shouts, and ah, Katsuki should’ve jammed the other door while that shitty attendant was inside, damnit. No weapon in sight but he has spotted him, so he needs to change spots, quickly. God, this tunnel better fucking-
A bright light blinds him. He blinks his eyes open to a shimmering blue sea, and grins. Perfect. Must be on a bridge. The tunnel continues again on the other end, so he grabs the sack (it yelps) and jumps off without hesitation.
“So long, sucker!” He yells, pointing the middle finger at the flabbergasted attendant as he falls towards the water. He lets go of the sack, closes his eyes and, with a great splash as well as a really painful impact, he hits the water.
He does nothing but sink for a while, holding his breath for as long as he needs. As expected, before long, arms carry him up to the surface and he opens his eyes and breaths in deeply.
Shouto is not impressed. “You can’t keep letting yourself sink just because I’m around.”
Katsuki frowns. “You need to stop getting yourself caught in nets, dumbass fish.”
Shouto dunks his head back in the water and Katsuki in turn instinctually grabs his face to push him down and himself up. Obviously, doesn’t go as planned, but when he comes up again for air he’s laughing and so is Shouto.
“Alright, fuck you. Closest land’s somewhere northwest. Could probably get another train back home. Think you can swim that far, treasure?”
“Of course,” Shouto says, and Katsuki wraps his hands around his waist and Shouto swims, homebound.