Cauldron ZETA

From the Sun Furrows Hunting Grounds, return to the Campfire at the southern, southwestern fork.

Take the road to the north, northwest.

Return to the fork and Campfire near where you met Erend.

Continue north and ford a river.

At the fork north of the river, turn west down a road a short distance.

Turn down the first road to the north to reach the Unflinching Watch Carja fort, which has a Campfire.

East of the fort's stairs, find an unmarked trail leading north through the hills.

Dispatch any Scrappers in the hills.

Continue north until you find a road, follow it east, then northeast to reach Cauldron ZETA.

Outside Cauldron ZETA, three Stalkers lurk. Use tall grass for cover (press the cover button to crouch behind walls or objects). Use Shock Arrows to stun them, focusing on one at a time if possible, then finish them with Critical Strikes and impact damage-boosted arrows.

Find a stand-alone pillar to the south with hand-holds. Climb to the top.

Turn west and leap a gap to reach a ledge with a Redeye Watcher. Defeat it.

Continue north until you find a secret entrance to the west, bypassing the force-field blocked main entrance.

Override the door at the end of the secret passage.

Continue down the linear tunnel until you reach a ledge overlooking a natural stone cavern.

Drop down into the cavern. Loot the Supply Crate.

Turn west and loot another Supply Crate.

Loot a third Supply Crate to the north.

Turn west, jump off a ledge into some water, and swim to the western shore.

Climb onto dry land and loot two more Supply Crates.

Dive into some water to the west, or descend carefully down ledges into shallow water.

Go through a triangular wire to the south, southwest to reach the Cauldron Core chamber.

Rappel down to the floor. Kill the two Watchers patrolling the energy bubble.

Climb a tower and override the Discharge Pylon to start the Thunderjaw fight.

Warning: The Thunderjaw is a dangerous machine. It has Blaze Canisters, a Data Nexus, two hip-mounted Disc Launchers, Freeze Canisters, a Heart, Power Cells, a Radar (your minimap with nearby blips and threats marked) on its back, Cannons on its face, and a tail. It can charge, perform tail sweeps, shoot lasers from its mouth, energy bolts from its Cannons, and air strikes from its Disc Launchers.

To defeat the Thunderjaw: Knock off a Disc Launcher with a Tear-damage modified Shadow Hunter Bow or Shadow Sharpshot Bow.

Shoot the Thunderjaw with Freeze Arrows (a modified Shadow War Bow takes about six shots or two Triple Shots).

When frozen, pick up the discarded Disc Launcher and shoot the Thunderjaw. Hitting weak spots deals massive damage, but body shots are effective. Emptying a Disc Launcher can take it from full health to a quarter health or less.

Try to freeze the machine again and finish it with normal arrow shots, or go after the other Disc Launcher.

Once the Thunderjaw falls, loot it for its drops, which usually include three purple mods and resources.

Override the Cauldron ZETA Core.

Ride the elevator up.

Head south through the large triangular door, which is now unsealed.