The train network in Big Walk is one of the most useful systems in the entire game. Once it's running, you can travel across the map without backtracking on foot, and it gives your co-op group a shared space to regroup and communicate. The catch is that the network starts completely offline, and getting it up and running requires solving the Blue Tower Puzzle from start to finish. Here's exactly what you need to do.
How to activate the train network in Big Walk
The train network stays locked until you complete the Blue Tower Puzzle. This tower follows the same general structure as the Red Tower and Green Tower puzzles, so if you've already worked through either of those, the format will feel familiar.
Big Walk Guide: How to Unlock & Activate the Train
How do you reach the Blue Tower?
Getting to the Blue Tower depends on where you are in the world. If you're coming from the Red Tower, head left on the map and you'll find it. If you've already cleared the Green Tower, the chairlift from that area connects directly to the Blue Tower, making it the faster approach. Either route works, so go with whatever fits your current progress.
Step 1: Solve the 5 surrounding puzzles
Around the Blue Tower, there are 5 puzzles to solve. Each one is found in the surrounding area, so explore thoroughly rather than sticking close to the tower itself. Completing each puzzle rewards you with a gold-shaped collectible.
Collect all 5 before moving on. These items are what unlock the key mechanism at the top of the tower.
Step 2: Place the collectibles on the Blue Tower roof
With all 5 collectibles in hand, climb to the roof of the Blue Tower and place each one into the empty slots. Once all slots are filled, the key unlocks.
Step 3: Shape the key using the blue machines
Five blue-colored machines are located near the tower. Each one contributes to shaping the key into its final form. Work through all five machines in sequence to finish the key. Once it's complete, the train network is restored.
How to use the train network in Big Walk
Once the network is active, head to any train station on the map. Check the schedule board at the platform to see when the next train is arriving, then wait for it to pull in and stop.
The train isn't the fastest way to cross the map, but it offers something more valuable in co-op: a shared environment where your group can regroup, communicate, and plan. After testing the full puzzle sequence across multiple runs, the train becomes noticeably more useful the further you get into the game, especially once the map opens up.
What's the best order to tackle the towers?
The Red Tower comes first since its puzzles are the starting four that gate the broader world. After that, the Green Tower and Blue Tower can technically be approached in either order, but completing the Green Tower first gives you chairlift access that makes reaching the Blue Tower faster. If you want the train running as early as possible, prioritize the Blue Tower right after the Green Tower.
For everything else you need to progress, the full Big Walk guides collection covers the map, the full ending, collectibles, and more in one place.