The town lock in Graveyard Keeper 2 sits over a stretch of fertile river bottom that stays flooded until you drive out the zombies holding it. Clearing it runs through a two-part tower defense fight called Operation POTATO, and winning both halves drains the basin so settlers can arrive and start farming it. The game is built by Lazy Bear Games and published by tinyBuild.
Quick answer: Beat Operation POTATO Part I and Part II at the town lock. The area drains, settlers emerge from the sewers to build farms, and a fast-travel point activates at the lock.
What Operation POTATO is
Operation POTATO is a lock-defense encounter split into two consecutive battles. You start it by talking to the guards stationed at the bridge beside the lock, who hand over control of the defense. Both parts use the same combat system seen across the town’s district fights: blue banner circles mark the point you have to hold, red arrows show where zombies attack from, and red capture circles mark the ground the enemy is trying to take.
Part I is the more conventional of the two. You set up defenses around the contested square, place archer towers and banners, and fend off incoming waves until the timer clears. Winning Part I pays out Gratitude Scrolls and leads straight into the second battle.
Part II changes the rules. You defend the banner without the squads you’d normally spawn in to help, leaning almost entirely on archer towers and your own positioning to survive the waves alone.
Clearing Part II ends the encounter. A Win! rewards panel appears over the barricade area, confirming the lock is secure and the fight is over.
What clearing the lock unlocks
Once both parts are won, the lock drains and the river bottom becomes usable land. Settlers then travel in through the sewer system and begin establishing farms in the basin. You’ll see them gather around the open sewer hatch as they move in.
The settlers come with a condition. They refuse to work with low-quality gear and immediately ask for steel tools, which starts a quest for high-grade steel. That request points you toward the Royal Foundry, where better toolmaking lives.
A fast-travel milestone also becomes available at the lock the moment the area is secured. Activating it lets you teleport straight back home and return to the lock later without the walk.
Here is what the win delivers at a glance.
| Outcome | Effect |
|---|---|
| Lock drained | River bottom opens up as farmable land |
| Settlers arrive | Move in via the sewers to build farms |
| Steel tools quest | Settlers demand high-grade steel tools |
| Fast-travel milestone | Teleport point activates at the lock |
| Gratitude Scrolls | Awarded for completing the battles |
How the lock fits the wider farming and steel path
The lock is one piece of a chain of district battles that keep opening new ground and new suppliers. A separate fight, the Battle at the Lake, has to be won to convince the bridge guards to lower the drawbridge to the Western Lake stilt houses. That is where Master Woodcarver Harold lives. Harold agrees to supply specialized timber, but only after you deliver 2 Building Kit I and 2 Iron Kit II to repair his river wood-catching machine.
The sewer combat arena, Sewerena, is another of these encounters. Defending its banner through a two-pronged zombie assault pays out additional keys and resources that feed into town progression.
The steel tools the lock settlers demand tie back to the Royal Foundry. Access to the Foundry and its steel technology is gated behind Jack’s questline reaching reputation level 70 and completing the district defense battles attached to it. In other words, satisfying the farmers who move into the drained lock runs through the same combat loop that cleared the lock in the first place.
Why the farming payoff matters
Farming feeds nearly every production system in Graveyard Keeper 2, from cooking and brewing to winemaking and alchemy, so the extra fertile ground the lock opens is worth the two fights. Crops still grow in garden beds by your house, vine trellises in the vineyard, and the orchard, and the basin farms expand that base rather than replace it.
Keeping too many active zombies triggers the “Excessive zombies” debuff, which weakens your church sermons until you upgrade the town PR machine and run a PR campaign. It is worth managing alongside the farming push, since sermons are a main source of faith and money.
Clearing the lock, then, is the point where combat and farming meet. You fight through Operation POTATO, the water drains, settlers arrive to work the land, and their demand for steel tools sets the next stretch of progression in motion.
