The Below the Surface side mission in Borderlands 4 is a grim but rewarding journey through one of the game's darkest underground labs. Ted, a survivor of Borderlands 4 Boosting cruel Order experiments, asks for your help rescuing those who didn't make it out. What begins as a simple favor quickly unravels into a harrowing dive beneath Dominion City. This guide walks you through every step - from finding the mission to facing its haunting conclusion - along with all objectives, enemies, and rewards.

How to Start "Below the Surface"

Pickup Location: Speak to Ted on the north side of the Terminus District in Dominion City.

Rewards: XP, Cash, Weapon (Uncommon–Epic), Vehicle Paint Job, Weapon Skin.

When you first talk to Ted, he'll explain his escape from the Order's Hydrus Sublab - a facility where inhumane experiments were performed. He'll hand you a key card to gain access and plead for you to finish what he couldn't.

Entering the Hydrus Sublab

The lab's entrance is heavily guarded by Order troops, so prepare for a firefight before approaching the bulkhead door. Once the enemies are cleared, use Ted's key card on the console to open it.

Inside, you'll find an elevator that's supposed to lead deeper into the lab - but it's broken. Instead, you'll need to locate an alternate route down.

Finding Another Way In

Face the entrance door you just came through, then look to the right-hand side of the room. Behind a stack of crates, there's a vent door you can open with your grapple. Crawl through the passage until you reach a hallway leading to a large elevator shaft. Drop down to reach a flooded underground tunnel filled with corpses - a grim preview of what's to come.

Follow the tunnel until you find a ladder at the far end. Climb it to emerge in a control room overlooking the labs. There's an ECHO Log on one of the panels here that gives more insight into Ted's past and what the Order was doing.

Navigating the Lab and Finding the RD Area

Continue through the next section until you encounter a bloody vent shaft with claw marks. Crawl through, but be ready - a Creep ambushes you on the other side. Dispatch it and enter the next area, where you'll find more Creeps roaming freely, having wiped out the scientists who once tormented Ted and others like him. Clear them out, then search the area for additional ECHO Logs if you want more lore.

Ted will radio in, urging you to locate the RD lab and destroy whatever technology remains. Follow the path through a busted bulkhead door, leading you deeper into the sublab.

Eventually, you'll reach a dead end with an ammo vending machine. Restock if necessary, then look up - there's a vent shaft above. Grapple into it and crawl through to drop into the RD lab below.

Clear the RD Lab and Reactivate the Elevator

The RD lab is swarming with Creeps. Eliminate them, and Ted will say he's on his way to destroy the facility himself. However, you'll need to reactivate the elevator so he can reach you. Go up the stairs in the back of the room and press the button on the console to bring the lift back online.

Survive the Vile Experiment Attack

While you wait for Ted's arrival, several mutated enemies labeled Vile Experiments will attack. These Creeps are enhanced versions with more health and damage, so use elemental weapons and explosive gear to handle the waves efficiently.

Once the final wave is defeated, Ted arrives at the lab. Speak with him, and he'll mention feeling a strange pull to the place - an urge to return to where it all started. Against your warnings, he steps into one of the machines used in the Order's experiments.

Final Boss: Vile Ted

In a shocking twist, the machine reacts to Ted's presence and mutates him into Vile Ted - the final boss of this mission. He fights like other Vile-class enemies but hits harder and moves faster. Use high-damage weapons and abilities to keep him staggered, and take cover when he uses area-of-effect attacks.

Once defeated, Ted drops loot and an ECHO Log, revealing his final thoughts and confirming that his transformation was irreversible. Collect the log for completion and grab any valuable Borderlands 4 Items he leaves behind.

Escaping the Facility

With Ted gone, a door at the back of the lab unlocks. Go through it and follow the long hallway to another elevator. Before leaving, pick up one last ECHO Log next to cheap Borderlands 4 Boosting a fallen scientist beside the elevator switch. Flip the switch and ride the lift back to the surface.