Arc Raiders A Toxic Trail quest walkthrough (Dam Battlegrounds)

A Toxic Trail in Arc Raiders continues the water contamination storyline on the Dam Battlegrounds map. The quest sends you back to the same drain where you first found a toxic barrel, then pushes you a short way into the swamp to identify who sabotaged the water supply and to pick up a valuable key for later raids.

Quest overview and prerequisites

A Toxic Trail is part of the broader water contamination chain that begins with Source of the Contamination around the dam’s Water Treatment Center. By the time this quest appears in Speranza, you should already know roughly where the first barrel was dumped.

The quest has three objectives:

Return to the water intake below the Water Treatment Control building and approach the contaminated barrel.
Search the nearby swamp to find the barrel’s origin, a truck submerged in the river, and take a photo of it.
Search the truck for clues about the saboteur, which drops a Spaceport Warehouse Key.

Extraction is not required to tick the quest objectives, but leaving with the key safely stored is strongly recommended, since it opens extra loot on the Spaceport map later.

A Toxic Trail is part of the broader water contamination chain | Image credit: *Embark Studios (via YouTube/@TroubleChute Basics)*

A Toxic Trail quest location (Dam Battlegrounds)

The quest plays out entirely on the Dam Battlegrounds map, centered around the Water Treatment Center and the swampy river that runs past it.

The key points are:

Water Treatment Center / Water Treatment Control building – main landmark on the dam where the drain and first barrel sit just to the north, at the water intake.
Swamp and river – shallow, murky water stretching north and west from the plant, with a visible flow that guides you toward the submerged truck.
Central Swamp Lift – an extraction elevator close to the truck, useful once you’ve grabbed the key.

Spawns will vary, but the quest’s objective markers reliably pull you into this small area around the dam and swamp, so the run is short and contained once you know the route.

A Toxic Trail takes place on the Dam Battlegrounds around the Water Treatment Control facility | Image credit: *Embark Studios (via YouTube/@TroubleChute Basics)*

Return to the contaminated barrel

Load into Dam Battlegrounds with a regular paid loadout rather than a free one if possible. The Spaceport Warehouse Key you obtain is worth keeping, and losing it due to a failed exfil or lack of a safe pocket can be costly in later raids.

Navigate to the Water Treatment Control building. Approach it from the north side through the swamp, the same way you did during Source of the Contamination, aiming for the drain and water intake area just outside the facility.

Move into the filthy water by the drain and get close to the familiar toxic barrel. You do not need to manually interact with the barrel or press any key here; simply walking near it is enough for the quest to register the objective and push you to the next step.

Get close to the toxic barrel | Image credit: *Embark Studios (via YouTube/@TroubleChute Basics)*

Once the game updates your task to searching the swamp for the barrel’s origin, you can leave the intake area and follow the river.

Search the swamp for the barrel’s origin (finding the truck)

The second phase asks you to “search the swamp for traces of the barrel’s origin.” In practice, that means tracking the flow of contaminated water a short distance to a submerged vehicle.

From the barrel and drain, follow the river away from the dam. Head slightly west and then northwest along the watercourse. Stay in or very close to the water; the objective sits only a short walk from the intake.

Watch for a half-submerged truck sitting in the river with multiple toxic barrels loaded on its bed. It is relatively exposed in the swamp and positioned just northwest of the initial barrel location.

Find the half-submerged truck with toxic barrels | Image credit: *Embark Studios (via YouTube/@TroubleChute Basics)*

Approach the truck until you see the quest prompt instructing you to take a photo. Yellow interaction markers appear around the truck’s sides once you are close enough.

How to take the photo of the barrel truck

Capturing an image of the truck is the quest’s third objective and confirms you’ve identified the origin of the contamination.

Move to one of the yellow-marked points at the side of the truck. These markers represent valid angles from which the game will accept a photo.

When the interaction prompt appears (for example, “Take photo of the barrel truck”), press the standard interact key (default E on keyboard) to snap the picture. No separate camera item is required; the game handles the capture automatically.

Move close to the truck to take a photo | Image credit: *Embark Studios (via YouTube/@TroubleChute Basics)*

After the interaction completes, the objective will advance to searching the truck for clues about the saboteur’s identity.

Search the truck and get the Spaceport Warehouse Key

The final in-raid task is to inspect the truck for more information, which also rewards you with an important key.

Circle to the driver’s side of the truck and look for a yellow interaction icon near the cab door. This marks the search point for the “clues about the saboteur’s identity” objective.

Use the interact key on this icon to complete the search. The game will spawn a Spaceport Warehouse Key at the truck once the interaction finishes.

Interact with the driver’s side door | Image credit: *Embark Studios (via YouTube/@TroubleChute Basics)*

Pick up the Spaceport Warehouse Key and place it in your safe pocket if you have one available. While the quest itself does not strictly require extracting with the key, the item later grants access to valuable loot on the Spaceport map, so it is worth securing.

Pick up the Spaceport Warehouse Key | Image credit: *Embark Studios (via YouTube/@TroubleChute Basics)*

At this point, all in-raid objectives for A Toxic Trail are complete; the rest is about getting out alive.

Extracting safely from the Central Swamp Lift

With the key in hand, the nearest extraction is conveniently close.

Move from the truck toward the Central Swamp Lift, the elevator extraction point in the surrounding swamp. The distance is short, so avoid unnecessary detours.

Stay alert for other Raiders. The area around the swamp elevator is an obvious choke point and can be camped by players looking for easy kills and quest progress.

Call the lift, hold the position until it arrives, and ride it out to complete the raid with the key secured. If you die before extracting and are not using a safe pocket, the key is lost.

Back in Speranza, turn in A Toxic Trail to receive the follow-up quest The Stench of Corruption, which is part of the path toward unlocking the Warden outfit.

Completing the quest is part of the questline to unlock the Warden outfit | Image credit: *Embark Studios (via YouTube/@TroubleChute Basics)*

Once you know the exact route—from the intake barrel to the submerged truck and nearby lift—A Toxic Trail becomes a compact, efficient run. The main risk is other Raiders converging on the same objectives, so fast, quiet movement around the dam and swamp pays off, especially when you are carrying the Spaceport Warehouse Key.