Biome survey
Transit Hub

| World code | D3 |
|---|---|
| Branch | Down |
| Route status | Main route |
| Palette | rusted iron + patinated copper + amber signal + rail-red |
| Materials | metal_machinery |
| Resident on file | Dog |
| Controller on file | The Leash |
| File no. | WN-BIO-19 |
Field summary
Vehicle and route-control biome; auto-scrolling rail carts and freight elevators, junction switches, and rescued passengers who help solve the route.
Survey notes
The Engine's logistics center: a rail and elevator network connecting every underground zone, with sealed service lines reaching beyond the Down branch. Transit Hub is the engineered counterpart to Heartroot Valley — rails and schedules instead of roots. Its critical external routes are the sky-elevator service line up to Cloud Terrace and the coolant freight line to Farm Town, plus the Fungal Grotto resin route that feeds Foundry fabrication.
The malfunction collapsed the schedules. Trains run without passengers or stop mid-tunnel; junction switches reroute in real time. The hub is still the fastest way between zones — you just cannot predict where you will end up. The infrastructure works perfectly. It is simply no longer working for anyone.
Every main level here is a rescue: a trapped passenger, a courier stuck in a freight loop, a maintenance drone pinned behind a route gate. Once freed, the companion follows and helps — holding a switch, marking a hidden transfer, slowing a train cycle. This is Dog's leave-no-one-behind instinct made into play, right up until the Leash reveals the corrupted version: guidance that refuses to let anyone leave.
Levels on record (15)
- D3-1 Lost Platform 0 main
- D3-2 Endless Passenger Loop main
- D3-3 Turbo Service Tunnel main
- D3-4 Schedule Sync main
- D3-5 Freight Splitter main
- D3-6 Deep Freight Descent main
- D3-7 Resin Tanker Run main
- D3-8 Leash Claim Yard main
- D3-B The Leash Switchyard boss
- D3-C Sky-Elevator Dispatch trial
- D3-D Quick Rescue Relay bonus
- D3-E Turbo Bike Time Trial trial
- D3-F Freight Lift Defense Trial trial
- D3-G Resin Tanker Split Trial trial
- D3-H Leash Bike Break Trial trial