Sell Lemons Sewer Secrets & Rewards
Permanent sewer payoffs — Cosmic Vine harvest timing, UFO Key 2× investor bonus, hidden Lemon X zone, and why you should rejoin between key runs. Lever routes live on the sewer map.
By Bloxron Editorial Team · Last updated
The sewer maze hides two permanent payoffs — a timed Cosmic Vine harvest and the UFO Key's 2× investor bonus plus hidden Lemon X access. This page covers what each reward does and when to claim it. For lever locations, colored-door routes, and the interactive layout, use the sewer map.
Important: rejoin between keys
Doing the Sewer Key and UFO Key back-to-back in the same server can bug the levers (stuck up or down). Leave and join a new server before starting the second key.
Cosmic Vine (Sewer Key)
- You can walk the maze to the vine without a key — it just takes longer
- The Sewer Key unlocks a shortcut gate permanently
Sewer Key route
Quick lever order: Blue ON → Red ON → Green ON → Red OFF → Blue OFF → Purple ON → Red ON. Marked step-by-step on the sewer map.
Cosmic Vine harvest
Each harvest pays out roughly half an hour of your current income rate as instant cash. The timer resets every four hours in real time.
After Evolution (rebirth), harvesting the vine in the first minute of a new run is one of the fastest ways to recover income — the payout scales with your stacked Alien Investor bonus. See the post-evolution rebuild steps on the rebirth guide.
UFO Key — 2× investor bonus
Reward: permanent 2× cash per investor (Good Samaritan Badge). This stacks with your Alien Investor pool and helps push toward the +32% max per investor on the rebirth wiki. The key also unlocks a hidden Lemon X zone — see Income Sources → Lemon X.
Requirements & route
- Requires at least one Evolution (rebirth) before the gray UFO Key appears
- Join a fresh server before starting — see the rejoin note above
- Full 14-step lever route with Homeless Alien dialogue on the sewer map