If you’ve been exploring the sewers in Sell Lemons and noticed players talking about the UFO Key, you’re probably wondering how to unlock it yourself. Unlike the Sewer Key, this one requires a much longer setup because several lever combinations have to be activated in the correct order before the key will even appear.
The most important thing to know before starting is that the UFO Key will not spawn unless you have already unlocked the Rebirth feature. Once Rebirth is available, head over to John the Alien on the surface. After that, you can begin working through the sewer puzzle.
Before You Start
The sewer system is essentially one giant maze controlled by colored levers. Every lever opens certain passages while closing others. Because of this, you’ll often need to pull a lever, then return later and switch it back.
A useful trick is resetting your character after activating a lever. This saves a huge amount of time compared to navigating all the way back through the maze.
Step 1: Activate the Blue Lever
Enter the sewers and make your way toward the Blue Lever location.
Once you find it, interact with the lever and activate it.
This is the first switch required for the UFO Key route.
After activating it, reset your character to return to the surface quickly.
Step 2: Activate the Red Lever
Head back into the sewers and locate the Red Lever.
Pull the lever to open a new section of the maze.
Don’t continue through the newly opened path yet because there are still additional switches that need to be configured first.
Step 3: Activate the Green Lever
From the sewer entrance, follow the route leading to the Green Lever.
Once you reach it, activate the switch.
At this point, three different lever states have been changed, opening access to new portions of the maze.
Reset again to save time.
Step 4: Return to the Red Lever
This is where the puzzle starts becoming confusing.
Go back to the Red Lever and interact with it again to reverse its position.
Many players think they’ve made a mistake here, but this is actually required. Certain doors only become accessible after changing the Red Lever back.
Step 5: Activate the Purple Lever
Now travel deeper into the maze toward the Purple Lever.
Pull the Purple Lever when you find it.
This opens another set of pathways needed later for the UFO route.
Once activated, reset your character again.
Step 6: Toggle the Red Lever Again
Return to the Red Lever one more time.
Switch it back.
The sewer puzzle constantly changes which routes are available, so this lever ends up being used several times throughout the process.
Step 7: Disable the Green Lever
Head back to the Green Lever and interact with it again.
This should return it to its original state.
While it may seem strange to keep reversing switches, the UFO route requires a very specific lever combination.
Step 8: Disable the Red Lever
After changing the Green Lever, return to the Red Lever and switch it off again.
Once this is done, the hidden UFO Key route becomes available.
Finding the UFO Key
With all required lever combinations completed, return to the sewer section marked by the green signage.
Follow the newly available route deeper into the tunnels.
Eventually you’ll arrive at a hidden section containing the UFO Key itself.
Pick up the key to add it to your inventory.
If the key does not appear, double-check that:
- Rebirth has been unlocked
- You spoke with John the Alien
- Every lever was activated in the correct order
- Red and Green levers were toggled back when required
Missing even one switch will prevent the key from spawning.
Using the UFO Key
Obtaining the key is only half the process.
After collecting it, you’ll need to adjust the sewer lever setup again to gain access to the alien’s location.
Return to the Red Lever and activate it.
Next, return to the Green Lever and activate it as well.
With both paths configured correctly, make your way through the newly opened route that leads beyond the normal sewer sections.
Eventually you’ll discover John the Alien hidden inside the underground area.
Interact with him while carrying the UFO Key.
Good Samaritan Badge Reward
Speaking with John after obtaining the UFO Key rewards you with the Good Samaritan Badge.
You’ll also receive a permanent boost to your Investor Bonus, making the entire puzzle worth completing even if you’re not specifically hunting badges.
Because the reward is permanent, this is one of the most valuable hidden secrets currently available in Sell Lemons.
Is the UFO Key Worth Getting?
Absolutely.
The puzzle takes some time because of the constant lever switching, but the permanent Investor Bonus upgrade alone makes it worthwhile. On top of that, the Good Samaritan Badge is one of the more interesting hidden collectibles in the game.
If you’re already exploring the sewers for secrets, completing the UFO Key puzzle should be high on your priority list.