Arknights Endfield: How to Drain the Water in “Treasure Beneath the Pond” Mission – Location, Quest, and Rewards Guide

What to know

• Drain the pond at Tianjing Courtyard using Fluid Pumps and pipes, which takes about 11 hours or less with multiple setups.

• Collect three keys inside the ruins using your Jet Drone to solve puzzles and unlock mechanisms.

• Rewards include T-Creds, Protoprism, Oroberyl, Operational EXP, and access to treasure chests.

• Located in Wuling City during Chapter 2 Process 2 as an Exploration Mission.

In Arknights: Endfield, you need to drain the water in Treasure Beneath the Pond mission to reveal ancient ruins packed with puzzles and loot. You tackle factory-building mechanics head-on here, setting up pumps to access the Tianjing Courtyard below.

Location (Tianjing Courtyard)

You explore the drained Tianjing Courtyard ruins in Wuling City, navigating underground paths filled with destructible boxes, gaps, spinning wheels, and locked gates. The area centers around a main path leading to a courtyard with three key mechanisms, side alcoves for keys, and a final cave revealing family lore tied to Tianshi Bao and Du Qusheng.

How to drain the water in Tianjing Courtyard

Set up your fluid extraction system precisely to pump out roughly 400,000 units of water from the pond. Start early since it runs in real-time, and you can speed it up with extra pumps connected via convergers.

Required Equipment

Before heading to the mission site, ensure you have manufactured enough hardware to handle a large-scale fluid transfer. You will need:

• Fluid Pumps: Bring at least 3 or 4 to increase the drainage speed.

• Fluid Tanks: These are essential for storing the water. Each tank holds 500 units. It is recommended to have about 20 tanks to minimize the number of times you need to reset the system.

• Pylons and Power: The pumps require electricity to function, so bring enough pylons to connect the site to your power grid.

Setting Up the Drainage System

Step 1

Once you arrive at the pond and speak with the NPC on the edge, you can begin construction.

Step 2

Position your pumps at the edge of the water.

Interacting with them will show you the current water levels (starting at 40,000 units).

Step 3

Place your fluid tanks in rows, roughly one block apart to leave room for piping.

Connect the fluid pump to the first tank using a pipe, then link subsequent tanks in a chain. Water will fill the first tank to 500 units before overflowing into the next.

Step 4

Place a pylon between your pump clusters to provide energy to the entire setup.

Managing the Process

Draining 40,000 units is a time-consuming process. To complete the mission efficiently, you must manage your storage capacity.

Step 1 – The Reset Method

When your fluid tanks are full, enter Build Mode and use Stash Mode (X) to pick them up.

This action instantly empties the water and places the empty tank back in your inventory.

Step 2 – Re-Deployment

Place the empty tanks back into the existing pipe network. You do not need to remove the pipes themselves; just snap the tanks back into place to resume drainage.

How to complete Tianjing Courtyard exploration

After draining, speak to Tianshi Bao for the Jet Drone hint, then descend. Equip fluid in your Jet Drone for shooting red spinning wheels.

Step 1: Open first doors

Follow the path down.

Shoot the first red spinning wheel to open the door, then the next inside.

Step 2: Grab first key

Go right, destroy box for Tianjing Courtyard Key 1.

Step 3: Access second key area

Return to main path, clear two boxes in alcove, drop gap to wheel; shoot platform down, hop on, ride up to cross.

Step 4: Activate crossing for key 2

Clear boxes, shoot hidden wheel to raise platform, hop across for Tianjing Courtyard Key 2.

Step 5: Reach third key

Main path to cave; shoot wheel by locked door (use water fluid), enter, climb boxes to shoot wall hole wheel.

Step 6: Open central gate

Shoot metal gate with Jet Drone, grab Tianjing Courtyard Key 3, drop to courtyard cutscene.

How to activate the gate mechanisms

Place the three keys into the courtyard mechanisms to unlock the large gate. Enter for a note cutscene revealing the treasure as old brew, then climb rope north to exit.

Rewards