Argent D'Nur

Argent D'Nur is a location and the final level of Doom (2016). The shattered remnants of the city of Argent within a mysterious world long ago conquered by the demons, crushed by the Icon of Sin, and absorbed into Hell, it was the home of the Night Sentinels and the location from which the Doom Slayer is thought to have gained immense power for fighting against the demonic hordes. It is the location of the source of Argent energy, the power produced by the Elemental Wraiths, known as "The Well," which is also the name of the thirteenth and final mission which takes place there. The Spider Mastermind serves as the boss of this level. By destroying it and exercising the powers of the Crucible, the Hell portal on Mars created by Olivia Pierce can finally be sealed.

"By destroying VEGA, you've created a portal directly into the heart of Hell. Now you must find your way to the source of the UAC's power known as The Well. The Crucible will allow you to absorb and contain the energy of The Well for good."

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Description
Information decoded from the Corrax tablets indicated that the battle to absorb Argent D'Nur was one of great significance to the demons and began an acceleration of Hell's dominion. A dimensional fracture in this area connects to the Argent Fracture on Mars, and is the source of the UAC's Argent energy. The Corrax tablets include a quoted passage referring to the area: "All falls before the command of Hell, for our power is absolute, our march to victory inevitable. Before our armies, even the Elemental Wraiths of Argent D'Nur were subjugated. In that great victory the Night Sentinels, protectors of the Wraiths, were betrayed by one of their own, and the wretches wept as we devoured their world and took The Well for our devices. None stand against us, for treachery resides in all things and we shall set it free."

- Corrax tablets

Mission 13: The Well
The destruction of VEGA propels the Doom marine into the ruins of Argent, a city on the world of Argent D'Nur that was absorbed into Hell following the unleashing of the Icon of Sin against that world. Despite fierce resistance from the demons, the marine fights his way to The Well and stabs the Crucible into the captive souls of three Wraiths, releasing the souls and shutting off the transfer of their energy to Mars. After releasing the final Wraith, the marine drops into a pit and finds a blood-stained and white-eyed Olivia Pierce waiting for him, who whispers "They promised me so much.", before being pulled into a blood pool and transformed into the Spider Mastermind. The marine manages to fatally weaken the Mastermind before finishing it off with a point-blank shot from the BFG-9000, after which he is tethered back to Mars. When the marine returns, however, Samuel Hayden takes the Crucible away and explains that the world must have Argent energy as things will be worse without it, and that the marine cannot be allowed to interfere; he tells the marine they will see each other again, before sending the marine to an unknown location as the credits begin to roll.

Objectives

 * Close The Well
 * Access The Well Cathedral
 * Lay the wraith's souls to rest (0/3)
 * Find the exit portal

Essentials
Head forward until you see some steps on your left, go down them then follow the path until you can jump down to an arena with fighting imps and cacodemons which will be followed by Hell knights, summoners, revenants, pinkies and mancubi; use the berserk powerup on the stairs to slay as quickly as possible. Once the arena is finally clear, go up the open door by the blue portal at the very top of the arena to enter the Well Cathedral then head straight forward until you reach a pair of Night Sentinel statues. Look right at this point to see an outcrop with armor shards that you can jump to then start following the ledges along the chasm, killing any cacodemons and lost souls that impede your progress. At the end of the chasm, you can jump down to a sandy path which leads to the first Wraith arena.

The first arena initially contains a knight and imps, but they will be followed by revenants, Hell razers, pinkies and spectres; make full use the quad damage powerup on the bridge running through this area. A pair of gates will open allowing you to climb some staircases with a Gauss cannon and other supplies at the top as well as the first Wraith; stab the Crucible into it to destroy it, and you will see a Sentinel spirit pointing in the direction of the second Wraith. Head back down the stairs and look right to see a jump pad that will propel you to the floor above, climb on the stone block in front of you to find a BFG core then jump into the mouth of the skull on your left to enter a tunnel which will slope upwards before dropping into the second Wraith arena, which spans multiple levels. Expect imps, razers and knights followed by a large contingent of revenants, cyber-mancubi and pinkies plus a baron of Hell; there is a berserk powerup on a ledge so get as many kills with it as possible. Head up the next set of stairs once the arena is clear to find lots of supplies including another BFG core, then turn round to see the second Wraith behind you; as before, after destroying it a Sentinel spirit will point you in the correct direction.

Head back down the stairs and look to your right to see a glowing green skull; inside it is a hole that leads down to another tunnel. Follow the tunnel as it curves round until you reach a metal doorway leading to the third and final Wraith arena. You will initially find some knights and pinkies along with a pack of imps, which will be followed by cyber-mancubi, revenants, cacodemons and three barons (this is your only opportunity to complete the Hold Still challenge so consider saving the quad damage powerup in this arena for that purpose). After killing all the demons, head through the yellow gates and climb the staircases to find the final Wraith. Go back down the stairs after destroying it to find that a pit surrounded by Sentinel spirits has opened; jump down it to begin the battle with the Spider Mastermind.

Spider Mastermind
The Mastermind is a highly durable foe, so this will be a battle of endurance as much as firepower. The Mastermind has a plasma cannon on its underside and can launch a spread of grenades from launchers on its sides; it may also project laser beams in all directions, including a laser from its plasma cannon that will sweep across your position. The Mastermind can also advance on you to swipe at you with its front claws, and leap to the side and flip itself over to dodge incoming fire. Blocks will rise from the floor that you can use as cover, but they will quickly be destroyed by sustained fire so do not rely on them too much. Fire everything you have into the Mastermind, throwing siphon grenades when possible, and aim at the exposed brain whenever possible to inflict maximum damage. A direct hit with the BFG will stun the Mastermind for a moment, interrupting whatever attack it was using, so use it tactically.

Once the Mastermind reaches 66% health it will begin electrifying the floor; if you see the Mastermind extend its arms, climb on top of the blocks but do not stand still or you risk being hit with purple lightning. The Mastermind can also electrify the blocks themselves, so do not go near the blocks when this happens. At 10-15% the heavily damaged Mastermind will not be able to move freely but it can still fire laser beams and telekinetically throw rocks at you, so do not underestimate its power as you close in for the kill. When the Mastermind finally runs out of health, wait for it to collapse to the ground then perform a glory kill to finish it off and complete the game!

Challenges

 * Hold Still
 * Kill two Barons of Hell with one shot.
 * The only opportunity to complete this comes in the third Wraith arena. There is a quad damage powerup in the arena which you should save until the barons have teleported in; once this happens, take the powerup then fire the BFG once both barons are within sight.


 * Uncharted Territory
 * Find all three "Skull Switch" secrets.
 * This challenge actually requires you to press three skull switches and then find the secrets they unlock; as a hint, all the secrets are behind wooden doors with red-eyed skulls. Refer to the "Special items" section below for the switch locations.


 * Big [REDACTED] Gun
 * Kill 25 demons with the BFG.
 * Use the BFG in areas that contain many demons. The further the BFG ball can travel, the more damage it will inflict and the more targets it can seek out.

Classic level
Follow the directions below to find the second "secret" skull switch, then go into the tunnel it opens. About halfway along the tunnel is a blood-stained wall with a lever under it, which will open the wall to your right and reveal the flesh-column room from Doom's. The only items inside it are an energy cell and a medikit.

Special items
After reaching the two Night Sentinel statues in the Well Cathedral, turn right and go forward until you pass under a stone arch. You will see the bottom of a staircase on your right leading up to the automap station.

The three skull switch secrets needed for the "Uncharted Territory" challenge are as follows:
 * 1) After entering the Well Cathedral, drop down one level and look to your right to see the first skull switch. After pressing it, climb back up to the ledge you just dropped off - the wide door to the right of the entrance has opened revealing a BFG core and a gas canister.
 * 2) The second switch is halfway up the left-hand staircase leading to the first Wraith. Pressing it opens a door near the skull that hides the tunnel to the second Wraith arena; behind the door is a tunnel leading to the classic level area as well as the lever that opens it.
 * 3) After entering the tunnel leading to the third Wraith arena, look right as you go up some steps to see the third skull switch. Press it then head back the way you came; a wooden door has opened revealing a BFG core and a mega health.