Justina, here is the story of the Snowpiercer(tm) fight scene.
Our heroes live in a dystopian future where climate change has made the earth uninhabitable. It is brutally cold and all of humanity has died out save for a handle of people that survive by living on a train. They didn't explain how living on a train is better than living in... well basically anything else. I guess we are just supposed to accept it and move on.
The story takes place 17 years after everyone got on the train. During this time a class system has developed where the people who live at the front of the train have luxuries and freedoms and the people at the back of the train have none. It is explained that this is an extension of the original boarding passes where the first class passengers have more amenities because they paid more. This class divide has gone to the extreme by years of enforcing it through violence and oppression. Our heroes are the lower class schmoes at the back of the train. The story is their struggle to move up to the front of the train.
The part of the movie I am going to tell you about is a fight scene shortly after our heroes break out of their confines and are making their way forward. They hotwire a door, and it opens to reveal a squad of goons.
The sunlight hits only our hero's face as he stares them down. The goons stare back. I think. You can't really tell. Their eyes could be closed for all I know.
The goons, despite living in a frigid, ice-cold deathworld, do not appear to know how to wear balaclavas. How did this even happen?
Goon 1: "How do we put these on?"
Goon 2: "Just put the eye-hole over the mouth part."
Goon 1: "Shouldn't we put the eye-hole where our eyes are?"
Goon 2: "We want to be able to talk, dur!"
Goon 1: "Makes sense."
So anyway, back to the story. The goons all point their faces at our heroes, but might not even know they are there. Maybe they just heard the door open and turned towards the sound. Some of them adjust the shoulders their hatchets and pikes are resting on, but nothing happens. Our heroes look back at the goons, slightly confused. The music starts to rise.
The heroes look confused. Is that a fish?
The front row goon displays the object. It's a fish alright.
He doesn't say it, but you can tell that Sidekick is all like 'WTF?' I was too actually. The hero though just seems concerned for the well-being of the fish. Don't hurt that fish you goon.
Do fish have necks? The fishmonger sinks his hatchet into the neck-area of the fish. Blood and guts spill to the floor.
Fishmonger hands the fish to his buddy. His buddy hands the fish back to the second row. I didn't hear anything, but I imagine he said 'Hey put this on the floor about ten feet back.'
Hero and Sidekick say double-wtf?
Now things start to heat up. The music ramps. After a few flinches and fake-outs, a legit fight breaks out. The clamour and uproar of the battlefield, (I mean train car), is deafening. It's a hectic, brutal, all-out battle for survival (on a fucking train car). Hero yells, "Move forward!"
Then with the clang of a knife ringing in our ears, the tone of the image fades to something like sepia. The only sound we hear is the heartbeat of our hero as he chops his way through dozens of morons who are fighting with balaclavas covering their eyes.
One by one they fall. Dead bodies cover the floor. Fish guts cover the windows.
Hero sees someone. It's the Fishmonger! He sets his steely gaze on his target and makes his way towards him. Seemingly nothing can stop this determined man.
Nothing perhaps, except a fish. That cleverly placed fish. Fishmonger is a tactical genius.
Whoopsie! Fish are slippery.
Hero down! He hits hard on the deck.
Fishmonger's fish hatchet swings! Hero rolls to the side just in time.
Hero sweeps the leg. Fishmonger goes down.
Hero sinks his hatchet into the neck-area of the fishmonger, spilling blood and guts everywhere.
"Hooked ya!" the hero thinks in a moment of reflection. "I reeled you in." he adds to himself. "You're a pain in the bass!"
"I got something on my face."
"It's Fishmonger's blood!!"
"Oh wait no, it's just fish guts."
"On the the next kill."
As the hero goes on to kill more goons, Sidekick looks on in awe. "That man is a hero."
So that, Justina, is the story of how Captain America avenged a fish in a world so frozen we can't live anywhere but on a train that never stops, but we somehow have access to decent sized trout.