Mortal Shell 2: Desolate Keep walkthrough (Part 16)

1. Enter the Desolate Keep.

If you recall, the entrance to the Desolate Keep was at the back of Sester Genessa's room in Marrow Keep, behind an illusory wall marked with a white symbol.

Head past the wall, and if you haven't already done so, cut all four chains connecting the censer to the walls. Once you've done that, interact with the censer to "Commune With Chaos", transporting you into the secret Desolate Keep dungeon.

2. Clear the lefthand passage.

Upon arriving in the Desolate Keep, you'll see a rectangular pool ahead of you. A Leechtongue is making its way from the pool to the lefthand side, where several Brigands are waiting. An Armed Knave is also slowly making its way from right to left on the far side of the pool.

Head into the pool on the righthand side and loot the 3x Weltcaps by the near pillar. Then cross the pool, and take out the Armed Knave first, while the Leechtongue is keeping the Brigands busy. Once it's dead, kill the Brigands and the Leechtongue (using the explosive barrels nearby if desired).

Watch out, though. These Brigands are scaled considerably higher than you've seen before, and they won't get staggered easily by your blows. Treat them with greater respect than usual.

Once they're dead, collect the 3x Weltcaps from the nearest corner of the pool to the Brigands. Then head further along this lefthand passage, and kill the next two Brigands at the base of the stairs.

Head up the stairs and you'll find another Armed Knave and three Brigands (two of them Crossbowmen). Kill them all. Then loot the various tables around you for 2x Burnt Effigies and 3x Common Moonshine. Also open the chest at the base of the statue for 500x Coin.

Double back down the stairs, and check behind the pillar to your left. You'll find a lever; pull it, and then head back to the pool. You'll see that there's a new ramp leading out from the pool into a courtyard. But we'll actually leave that for now and head in a different direction to reach the courtyard.

3. Fight through the main chamber.

Head along the left side (previously far side) of the pool. Around the next couple of corners you'll find an Armed Knave standing in front of what looks to be a dead end. Kill the Knave, then walk towards the dead end. The wall will open up, revealing a much larger main chamber.

This chamber is filled with enemies: a Headsman and several Brigands, as well as two Subjugated Sentries. These large enemies are amped up Stoners: instead of hurling boulders, their heads are ballistae which fire very powerful shots at you with less warning than their Stoner kin.

Bait the Headsman and Brigands away from the Sentries and kill them off carefully; then cross the chamber and kill the Sentries in melee.

Once the Sentries are dead, 5 more Brigands will appear in the chamber. Kill them all (again, they're hard to stagger and deal lots of damage, so don't get complacent).

Now you can loot the chest the Sentries were guarding for a Tooth Of Nochte, and also loot the 2x Common Moonshine on either side of the steps as well.

Once that's done, head around to the very back of the room. You'll find some Martyr's Ash to collect, and also a path forward in the corner. Kill the Subjugated Sentry in your way and head around the corner into the next room.

4. Kill the Necrite.

The next room has a zigzagging wooden platform running through another pool. A Leechtongue guards the platform, while the pool is guarded by various Bloodcursed Skulks (they're the same as regular Skulks but spew out Bloodcurse instead of Poison), and another Leechtongue. Kill everything in the room.

You'll also see there's a Brigand Stoner on an upper platform in the back-left corner of the room. You can never reach the platform the Stoner is on, so if you want to kill it, you need to use ranged weapons.

Collect the 11x Weltcaps in the pool, and then head over to the corridor at the far end. Ahead of you is a Necrite, like the one you saw all that time ago in Mushroom Village. Try to correctly time your parry of its sweeping first strike (which it holds longer than you might expect), and chop it down before it has time to respond.

5. Obtain the Blackmarrow Key.

Head straight on towards the far wall behind the Necrite. Again the wall will ascend out of view, revealing another room filled with explosive barrels, Wretches, and another Subjugated Sentry. Kill them all.

On either side of this room, you'll find grated walls, with Armed Knaves behind them. You can head around the far corners to access these side areas and kill the Knaves.

With that done, just head to the far wall of the room, and let it open the way for you. In this final room there's a chest; open it for another Blackmarrow Key, like the one you just obtained after defeating The Lost Child.

Behind the chest is the orb that will teleport you out of the dungeon, but don't use it yet. We're not quite finished!

6. Unlock the passage below the Stoner.

Turn around and head back into the room with the zigzag platform and the Brigand Stoner. Beneath the platform in the corner that the Stoner is/was on, a new pathway has opened up. It opened once you passed a particular invisible line in that last room.

The easter egg of the Desolate Keep... An extra tip from Ollie

It may only be apparent to a small subset of Mortal Shell 2's playerbase, but the entire layout of the Desolate Keep is lifted almost 1:1 from the first level of Doom. You can visit the E1M1: Hangar page on the Doom wiki to see just how similar the two levels are, down to the secret passages opened by crossing invisible thresholds! Pretty cool.

Head in and you'll find 3x Ventrium on the floor. There's (seemingly) nothing else in the room except a lever on the opposite wall which does nothing. In fact, the lever activates an elevator, but you need to reveal the elevator first.

To do so, head back into the zigzag platform room, and walk back from there towards the main chamber which preceded this room. Doing so will activate another invisible threshold. Now turn back and head into that secret room in the corner of the zigzag room again. You'll see that now there's an elevator beside the lever!

Ride the elevator to the top, and follow the path to find a Dorsalite on a throne. Unfortunately this secret passage still doesn't grant you access to the Stoner's ledge, so just drop off the ledge to your left to re-enter the zigzag room.

7. Kill the Grisha in the courtyard.

Just one more room to find, and it's the courtyard you spotted earlier. But there's another way to get there, which we'll discover now.

From the zigzag room, head into the adjoining corridor again where you fought the Necrite. Walk close up to the righthand wall, and it will open for you, revealing another secret passage.

Head down the steps, and kill the two Foul Knights that burst out of the iron maidens ahead of you. Then head up the steps around the next corner to enter the courtyard.

This courtyard is mostly empty of items of interest, although in the centre of the pool in the ground there's a Grisha. You know what to do.

When the Grisha dies you'll earn another Grisha Remnant, and you can also loot the item in the centre of the pool for a Glimpse. The only other things to loot are on the wooden execution platform in the near left corner of the courtyard, where you'll find 3x Martyr's Ash.

8. Exit the Desolate Keep.

That's everything! Now just backtrack out of the courtyard until you reach the corridor behind the zigzag room once more. Then head to the end of the dungeon where you looted the Blackmarrow Key, and activate the glowing light in order to transport yourself back out of the Desolate Keep.