The mission “Below the Surface” sends you into a flooded lab full of traps and enemies. The task tests your movement, aim, and how well you keep your gear loaded. The goal is to get in, find the R&D systems, break the key tech, beat the boss, and get back to Ted with proof Borderlands 4 Cash.
Start the mission by talking to Ted. Ted gives you the keycard you need to enter the Hydrus Sublab. Walk to Ted’s marker, open the talk menu, and accept the task. After you accept, check your map for the Hydrus entrance. The keycard appears in your inventory as a mission item, so make sure it is equipped or flagged.
Use the keycard at the Hydrus door to get inside. Approach the access panel, interact with it, and slide the keycard into the slot. The door will unlock and the dropship or hatch will open. Once the door is open, watch your footing as you go down. The lab has slick floors and broken platforms, so jump with care and avoid long falls that drain your shields.
Find an alternate route if the main path is blocked. The main corridor sometimes has sealed doors or flooded sections that you can’t pass at first. Look for vents, ladders, and maintenance shafts. Check side rooms and ledges for walkways that lead down. Use your grenade or your action skill to clear weak walls or to break power conduits that open new paths. If you see loose crates or scaffolding, use them as makeshift steps to reach lower levels.
Clear the resistance as you move deeper. The lab fills with security bots, armored guards, and mutated lab subjects. Target high-threat enemies first and use cover to reduce incoming fire. Throw grenades into groups and use area skills to control crowds. If a wave pins you, fall back to a choke point like a doorway or a corridor and fight from there. Keep spare ammo, medkits, and elemental rounds on hand for the tougher rooms.
Locate the R&D area and destroy the key systems. The R&D room has consoles, reactors, and marked test rigs. Walk up to each marked device and plant explosives or interact with sabotage prompts to disable them. If the mission asks you to destroy specific targets, watch the objective list for the next marker so you do the tasks in order. Break the glowing consoles and smash the data banks until the room reads as neutralized. This step often triggers the boss encounter, so stand ready.
Face CorrupTed and collect your reward, including extra Borderlands 4 Cash buy. The boss usually appears after you cripple the R&D systems. Learn its attack pattern, keep moving, and hit weak points when they show. Use the elemental types that work best against its armor. After you down CorrupTed, loot the chest and clear the room for extra drops. Search nearby lockers and hidden caches for Borderlands 4 Cash and rare schematics before you leave.
Return to Ted and claim your reward. Head back to the surface, find Ted at his marked spot, and speak to him to turn in the mission. Check your inventory for the mission reward and any emails or vendor messages that unlock after the hand-in. If the area still has loot, sweep it once more before you fast travel away. With the mission done, you should have new gear, experience, and some extra cash to spend on upgrades or ammo.
