Borderlands 4: Disallowed Leftward Side Mission (Full Walkthrough)

Disallowed Leftward is a short, combat-heavy side mission that runs entirely inside a single Tediore outpost. There is no long escort sequence and no fetch loop. You accept it from a console, punch through the garrison, and put down a caged experiment at the far end of the compound.

Quick answer: Accept Disallowed Leftward at the mission console in Tediore FOB Bravo Lima 4.2, place the extra Digi-Gauntlet on the marked pad, fight through Tediore Adjudicators and Troubleshooters to reach the enclosure, then kill Experiment C-23 to complete the mission.

Disallowed Leftward mission details

Everything you need to know before starting, in one place. The whole run takes only a couple of minutes once you know the route.

Detail	Value
Mission type	Side mission
Location	Tediore FOB Bravo Lima 4.2, Providence Island
How to start	Interact with the mission console at the outpost
Enemies	Tediore security, including Adjudicators and Troubleshooters
Boss	Experiment C-23, held in the enclosure
After completion	Boss replay point appears on the map

Where to find and accept the mission

Open your map and travel to Tediore FOB Bravo Lima 4.2. The mission sits inside the outpost itself, so you do not need to clear any surrounding area first.

Head to the mission console at the outpost and interact with it. Disallowed Leftward is listed there, and accepting it immediately places the first objective marker on your HUD.

Follow the marker to the red holographic placement pad and drop the extra Digi-Gauntlet on it. The objective clears the moment the gauntlet locks into position, and the outpost’s security turns hostile right after.

Place extra Digi-Gauntlet objective active while lining the device up with the red holographic pad — Lining up the extra Digi-Gauntlet on the red holographic placement pad. Image: Gearbox Software

How to reach the enclosure

With the “Reach Enclosure” objective active, push straight down the corridor toward the waypoint. Tediore forces spawn along the route and shoot as you advance, so use the cover on either side rather than sprinting through the open middle.

Reach Enclosure objective on the HUD while pushing down a Tediore corridor under fire — Pushing down the corridor inside Tediore FOB Bravo Lima 4.2 with the Reach Enclosure objective active. Image: Gearbox Software

Clear the Adjudicators and Troubleshooters that block the path. Adjudicators are the heavier of the two and will hold ground, so deal with them before you commit to moving forward.

Keep following the marker until you are standing at the enclosure door. Top up ammo and shields here, because the fight starts as soon as you step inside.

Player approaching the enclosure door with the Reach Enclosure marker still tracked — The enclosure entrance at the end of the route. Image: Gearbox Software

How to kill Experiment C-23

Entering the enclosure swaps your objective to “Kill Experiment C-23” and locks you into the boss arena. C-23 is an Animal Control target that closes distance quickly, so the arena’s open floor works against you if you stand still.

Keep moving laterally and use the enclosure’s perimeter to break line of sight when your shield drops. Circling is more reliable than backpedaling in a space this size.

Focus fire on C-23 rather than any adds that wander in. The mission only tracks the boss, and every second spent on trash gives it another opening to reach you.

Kill Experiment C-23 objective displayed while aiming at the Animal Control boss inside the enclosure — The Kill Experiment C-23 objective during the enclosure boss fight. Image: Gearbox Software

Finish C-23 off. The mission completes the instant it dies, with no follow-up objective and no return trip to the console required.

How to confirm the mission is complete

Two things confirm it. The mission completion prompt fires the moment Experiment C-23 goes down, and your map updates to show a boss replay point at the enclosure. If that replay marker is on your map, the mission is logged.

Note: if the completion never triggers, the usual cause is that C-23 is still alive somewhere in the arena rather than any objective bug. Sweep the enclosure before assuming something has gone wrong.

Loot and getting back to the vending machines

Experiment C-23 drops its loot inside the enclosure, so vacuum up everything on the floor before you leave. It is worth doing a full pass, since the replay point means you can come back for the fight later without redoing the approach.

Player collecting gear drops inside Tediore FOB Bravo Lima 4.2 after the boss fight — Collecting drops after the enclosure fight at Tediore FOB Bravo Lima 4.2. Image: Gearbox Software

Once you are done, use the purple teleportation orb in the area to warp straight back to the vending machines. That saves you walking the corridor again and lets you sell or swap gear immediately.

Disallowed Leftward is one of the quicker outpost missions in the game, and the only real difficulty spike is the enclosure itself. Bring a weapon you trust for a single sustained fight, keep your distance manageable, and the whole thing folds in a few minutes.