In this swampy region, make your way northwest until you reach a pool of water on the lower level. From here, look right and scan the nearby walls. Golden spheres embedded in the stone mark the area. Beneath one of these spheres, you'll find the last fragment. Grab it, and you're ready to Borderlands 4 Boosting open the Vault itself.

Locating the Carcadia Burn Vault Door

With all three fragments collected, your next objective is unlocking the Vault door. Travel to the Grindstone of the Worthy region. If you've already activated the Rustical Hurl Silo fast travel point, use it to cut down on travel time.

From the silo, head north until you're close to the Vault icon marked on your map. This is where things get tricky - the entrance is concealed. Look around the northwest side of the region for a debris-strewn area. As you approach, the hidden altar will rise from the ground, revealing the Vault door. Place your fragments, and the path inside opens.

Boss Guide – Defeating the Primordial Guardian Radix

Radix is unlike most bosses in Borderlands 4. Instead of overwhelming you with one-shot mechanics, the fight is a test of endurance and agility. The arena constantly shifts with hazards, and pangolin mobs will spawn in waves. These smaller enemies don't deal much damage, but they're valuable - they exist primarily to give you a chance to revive if you get downed.

Radix also carries an energy shield. Electric weapons are your best option here, since they can strip its defenses much faster. Keep in mind: the boss always spawns two levels above your character, so its attacks scale to remain threatening.

Here's a breakdown of Radix's moveset and how to counter it:

Flying Rocks: Radix slams the ground, raising rocks that orbit its body. These make it harder to close distance and attack. Later phases expand the rock wall outward, forcing you to reposition. Use ranged weapons or climb the rocks to maintain damage output.

Shockwave Combo: Often following the rock pillars, Radix slams the ground repeatedly, sending four shockwaves across the entire arena. Your best defense is mobility - jump or climb onto one of the rocks from the earlier attack to avoid the electric waves.

Charged Rock Shot: Radix raises its left arm, supercharges a rock with electricity, and launches it at your current location. Dashing sideways at the right moment will keep you safe.

Jump Attack: After burrowing briefly, Radix leaps at you with its electrified arm. Dodge laterally, but stay at a safe distance - the impact creates a damaging area around the landing point.

Underground Charge: Sometimes Radix deactivates its orbiting rocks and tunnels through the arena. While it rarely targets your exact location, the bombs it plants along its trail are dangerous. Stay alert and avoid glowing ground markers.

Tempest Storm: One of its flashiest abilities, Radix floats to the arena's center and begins channeling electricity. Blue circles appear on the floor - a clear warning for incoming lightning strikes. Dash out of danger zones quickly, saving at least one dash charge for emergencies.

The key to Borderlands 4 Items this battle is resource management. If you waste dash charges too early, you'll have no escape tools when Radix launches heavy attacks. Keep moving, deal steady damage, and use the pangolins as safety nets when downed.