This episode runs about 71 minutes and opens on a card reading "Episode 100" over the task signs in Basket Station. Basket weighs the one interesting job against the busywork, and after some back and forth with chat the pick is the top sign: "Caboose Token re-delivery feature from intersections." Lapis_Lauri is on the server too and says hello in chat.
Where the caboose tokens go
Basket rides out to the South Port Hypermine station and walks back to the nearest intersection to show the problem. A train pulls in tokens at an intersection to decide which way to go, and as it leaves, the intersection gives tokens back to any chest minecart with space. It never gives caboose tokens back, because an engine could pick one up "and then that would kind of break everything." So every intersection slowly collects caboose tokens, and over time the stations would run out.
A side that was never finished
Down in the machinery, things are worse than expected. The intersection holds extra north tokens it shouldn't have, so Basket drops them into a hopper to be picked up by a passing train. One chest has 19 caboose tokens just sitting in it, and the circuit meant to clear the other side was never finished. Nothing turns west or east there yet, so Basket never noticed. A new repeater and a test button later, it clears: "Okay great."
Two ways to hand them back
Basket lays out two fixes. A water stream could carry tokens from each intersection to the nearest station, but it needs a path underneath, and this intersection sits on a bridge. Or the intersection could detect a caboose going through and give it two caboose tokens back. That needs another spot where the track dips down, which Basket would rather have fewer of, but it wins.
Basket takes the train back to Basket Station for comparators, repeaters, hoppers, droppers, gravel and tokens. The tokens are cobblestone renamed on an anvil, and the caboose one reads "BRCABOOSE" in the tooltip, short for "Basket Rail Caboose."
Building the dip
Back by the intersection, Basket digs out the track bed and sets two hoppers under the rail where the cart dips, with a filter below that accepts only the named tokens. The cramped space fights back: redstone bleeds into the wrong blocks, a hopper is missing, and one signal powers the block it is meant to read. Once that is sorted, a seventh caboose token gets pulled down while six stay put. "That part works well."
The next part is three droppers to push tokens back up to a passing cart. On the first test the tokens move up only one step: "that's not really going to work." Basket starts on redstone torches to power the blocks beside them instead.
Out of time
That is where the time runs out. A check on the rail up top shows a torch the new wiring had switched off, so Basket pulls the line from another block and fixes the track. The sorter that pulls out caboose tokens works, but nothing hands them back yet, so for now every train going that way drops an extra caboose token. In Basket's words, it "makes the problem worse." The plan for next time: when the caboose is detected, send two caboose tokens up for it to grab.