It's more hilarious if it was spoken out loud, I think.
Summary (there's a shorter version at the bottom of this post):
Rook was listening to Amber talk about her backstory when he realized that his journal was missing. This freaks him out, as he is a treasure hunter and that journal contains a great deal of notes treasures and stuff. He requests the other ponies help him find it in exchange for him helping them get back on the right train.
Amber and Electro head to the train's bar, but get distracted and start geeking about video games. Meanwhile, Rook discovers his journal: it was stolen by a large and mean looking pony, who then proceeds to deck Rook in the face.
Amber and Electro run to the thugpony, but Ganaram attacks the thug with a chair, knocking him out. Rook gets up just in time for the thug's unicorn friend to steal the journal and run to the front of the train. Electro tries to tackle him, but slams his face into the wall. Electro owned count +1
Amber gets pissed and is about to chase the unicornthugpony, but gets distracted and goes to comfort Electro instead.
Rook and Ganaram chase after Unicornthugpony, tearing through the upper class train cart, knocking food carts over and starting fires (which are quickly forgotten about).
Meanwhile, Amber and Electro go about tying up Thugpony #1 so they can interrogate him when he wakes up or something, when Amber discovers that a third pony has stolen her bag, containing her expensive video game stuff. Amber accuses Electro of stealing it, but realizes that he didn't.
Meanwhile, Ganaram and Rook corner thugpony #2 in the engine room, and an epic brawl occurs. Thugpony is defeated, but teleports away with the journal.
Meanwhile, Electro and Amber track down thugpony #3 (the one who stole the video game) and chase him around. He soon drops the saddlebag and dissappears from the plot. Electro and Amber grab the video game bag and then talk to Rook and Ganaram about what happened, and the latter two explain that the journal theif got away.
With that in mind, they decide to go back and interrogate Thugpony #1, who started the mess, and that's where we are now.
TL;DR:
Rook has a journal containing valuable treasure-hunting notes, but it gets stolen by Thug 1. Ganaram knocks out Thug 1, but the journal gets stolen by his accomplace: Thug 2. Rook and Ganaram chase Thug 2 to the engine room and beat him up, but he teleports away. Electro hits his face again in the process.
Meanwhile, Amber and Electro get distracted by video games, but decides to tie up Thug #1. They get distracted again when Amber's video game gets stolen, but they get it back so no biggie. Amber and Electro talk to Ganaram and Rook, and they decide to go interrogate Thug #1 on where Thug #2 teleported to.