Episode 13 of Season 2 opens on a base that grew between episodes, now run by trains. Basket is replacing the old long assembly lines with small cells, each fed by its own train and making one thing: pipes, gears, and then engines. Midway the tank comes out to clear enemy nests so the wall can move forward. When the video ends, the trains are stuck in a jam that has no fix yet.
Busy between episodes
"So I've been busy." On the map, the commentary points out the copper and coal taken since last time and a wall pushed forward. One stretch went badly: the construction robots flew over enemy bases, "and so at one point I lost all of my drones." The lesson: expand in layers, so the robots never cross enemy ground.
The smelting now happens at train stops. One takes stone and makes bricks, others handle copper and steel, and two handle iron. Along the straight runs of track sit small production cells. One turns iron into pipes and another makes gears. Each gets its own locomotive and two wagons.
An engine cell
"So now I have like little pods that will produce a certain item." The next one is for engines, which need steel, gears and pipe. A template gets it started, then the belts are rebuilt by hand: pipes ride one side of a belt and gears the other, and steel loops around the outside. A stack filter inserter takes finished engines off the belt. The machines are set to engines, and the pipe and gear trains get a second stop on their schedules, "MoterMatDropoff", where they wait 30 seconds or until 5 seconds of inactivity.
Steel is the bottleneck, so some gets dropped in by hand to prime the line. A train held up on the way turns out to be waiting behind one that ran out of fuel, and the commentary notes a station that needs a coal feeder. The engines all go off to make more robots: "right now I have 576 construction drones they keep on dying."
Tank work
Next comes expanding the wall. The tank now fires shells that "puncture right through buildings." The biggest enemies shrug off the machine gun, so the tank pulls them back to the wall, where the turrets finish them. Between fights the commentary waits for a robot to fly out and repair the tank, and mentions a power shortage: "I need to build more solar."
One charge goes wrong and the tank nearly blows up. "Well, that was close." Running enemies over works, and an achievement pops up. Driving into the wall, the commentary warns, damages both the tank and the wall.
Building over the trees
With the area cleared, a new walled block goes down. The commentary shares a trick: holding shift while clicking places a blueprint even where things are in the way. More enemies show up ("I'll use my missiles"), and the plan is to secure this side before moving any farther out.
A traffic jam
Back at the factory, a new drop-off design takes four items, though part of it faces the wrong way and needs fixing in the template. The bigger problem is trains. With so many running, two lines block each other in a deadlock. Extra signals go in, and the commentary explains that holding shift lets a robot place one from a distance. One train loops back around and the jam stays. "Yeah, I'm not sure how to solve that one."
Where it ends
The commentary calls it "my train nightmare" and leaves it for next time. A short follow-up adds that temporary signals helped but came out again, after two trains got stuck in a loop. The video ends on the Rail chain signal in the crafting menu, which "reads the next signal in the path," not yet tried.