Secret Key Route

How to Get the Sewer Key

Stop running in circles. Follow this simple, step-by-step walkthrough to conquer the Sewer Maze, pull the hidden levers, and grab your key.

Steps to Get the Sewer Key in Sell Lemons

Step 1

Find the Sewer Grate

Head behind the main Lemon Depot (Tier III) building. You will see a glowing purple sewer pipe grate on the ground. This is a hidden map. Step on it to teleport down into the Sewer Maze. Warning: It is pitch black down here, so turn your in-game brightness up!

Step 2

The 5-Color Lever Protocol

Once you are inside the maze, you cannot just wander around. You need to find and pull 5 different colored levers in the exact right order. Follow this color sequence: Red -> Blue -> Green -> Yellow -> Purple. If you click a lever out of order, you will hear a buzzer sound and have to restart the whole sequence from the beginning.

Sell Lemons sewer maze lever sequence map
Step 3

Survive the Maze Traps

While hunting for the levers, look out for the glowing green sludge zones on the floor. Stepping on them slows your movement speed to a crawl, which completely ruins your run if you are trying to speedrun the maze. Use your 'Run Faster' alien power to skip over the gaps.

Step 4

Claim the Sewer Key & Badge

After pulling the final Purple lever, a massive steel vault door at the center of the maze will slam open. Run inside to grab the glowing Sewer Key floatin on the pedestal. The moment you touch it, you will instantly unlock the rare "Cosmic Farmer" Badge!

Pro-Tip: How to Use the Cosmic Cash Vine

Do not leave the sewer immediately after getting the key! Use your newly acquired Sewer Key to unlock the iron gate right next to the vault. Inside, you will find the legendary Cosmic Cash Vine. Equip your 'Expert Picker' power, activate your auto-clicker, and harvest the vine. It gives you a temporary 5x cash burst that stacks with your active base multipliers, allowing you to walk out of the sewers with trillions of dollars in pocket.

What's Next?

Now that you've mastered the underground maze and secured your early millions, it's time to heavily scale up your surface operations. Don't let your factory halt! Head over to our Best Progression Guide to break the developer's infamous Depot Decoration Gates and unlock your next tier nodes instantly.