The video opens on a title card, "Minecraft Aftermath Let's Play S1E01 with BasketMC," and then "Run for the Hills." Basket has just logged in to the Aftermath server for the first time. The chat says "Welcome to Aftermath, survivor!" and lays out the rules: "#1 No x-ray/radar/hacked clients" and "#2 See rule #1." Chat is ranged, "so nobody can hear you unless you're very close." Basket has seen a few videos of the server and knows the basics: a broken-down city, a zombie apocalypse, and "you can do whatever you want as long as you don't cheat."
Stuck in a tree
It's night, and Basket is perched in a snowy treetop with zombies crowding the ground below. "Whoa, that's a lot of zombies." The tree has a surprise of its own: "when I broke some of the main stem, a bunch of the leaves also broke."
So Basket stays put, crafts a few basics and waits for the sun. Morning works as hoped, and some of the zombies start to burn. Not all of them. "So this guy won't die because he has a helmet on." Basket goes after the leaves that shade the rest ("Let me get rid of the leaves") and comes down from the tree wearing a helmet.
Into the ruins
In daylight the city is huge: snowy streets, cracked towers and stone buildings in every direction. Basket starts checking them for supplies and mostly finds empty chests and empty furnaces. Other survivors only show up as chat lines, and one of them is having a worse day than anyone. "dylan_9000 got trampled by arachnids!" Then "dylan_9000 fell to the hunger of the horde!"
Deep inside one building Basket finds beds and tries one. The chat answers "Bed spawn set!" and "You can only sleep at night."
The building that keeps winning
That bed turns out to matter. A zombie comes up the stairs, and then "A creeper blasted BasketMC!" Basket respawns right where the fight was, with the stuff scattered nearby. "I think somebody stole my sword." Getting it back means going through the zombies and creepers that keep turning up in the halls. "There must be a creeper spawner or something."
It goes badly. "BasketMC was overwhelmed by zombies!" Somewhere on the server, so does dylan_9000: "A creeper blasted dylan_9000!" Each death drops Basket back in the same spot. "Well, this is certainly harder than I expected." Time to abandon ship.
Out through the floor
Basket finds a trapdoor in the floor and drops through it into the dark. "Well, I'm sure the sewers are gonna be safe." It works. The way leads out, and Basket comes up on the shore of a lake ringed by jungle trees. The new plan is to get out of the city entirely, where there "won't be as many spawners."
Somebody's hidey-hole
Basket chops a jungle tree, and the leaves break away as soon as they lose the trunk, the same tree rule as before. A gap in the hillside looks like a good place to dig in, but someone got there first. "This is somebody's hidey-hole, and not a very big one."
Basket moves in anyway. "We have two guys, can't get to us though." Out come a stone sword and pick, a furnace and charcoal, and by the end Basket is wearing a leather tunic.
There's no coal deeper in, so Basket walls off the tunnel to make a smaller hideout and calls it there. "We finally got out of the city." The end card runs to the close of the video, with no gameplay after it.