Mortal Shell 2: Winterglass Lake Beacon Location and Mornefrost Grave Cleanse

The Winterglass Lake Beacon is the checkpoint that opens up the Mornefrost Grave dungeon inside the Conquered Temple, and it is the only place to pick up the Immaculate Crown — the key item that makes the giant stone hands scattered around the frozen region move out of your way. Cleansing it also hands you the Fusillade Stone tarstone and an Ovum.

Quick answer: The Winterglass Lake Beacon sits at the bottom of the large multi-level structure in the Conquered Temple, reached through Sester’s Refuge and the snowy Valley of the Revered. Enter it, take the right-hand path at the three-way split to grab the Immaculate Crown, then defeat the Caged Grisha down the middle path and interact with the beacon core to cleanse the corruption.

Winterglass Lake Beacon location and route from Outskirts of Mammon

The Conquered Temple is a gate region, not part of the overworld map, so you cannot fast travel straight to it the first time. You reach it through the southeastern gate in Sester’s Refuge, which sits in the Ruins of Mammon. The Sester’s Bastion dungeon inside the Sester’s Gate Beacon needs to be cleared before the gate lets you through.

Fast travel to the Outskirts of Mammon Beacon and open the map. Set your course east toward the Abbey Entrance Beacon, which is the halfway marker on this run.

Mortal Shell 2 map screen with the Abbey Entrance Beacon selected on the route east — The map screen with the Abbey Entrance Beacon highlighted, the waypoint between Outskirts of Mammon and Sester’s Gate. Image: Cold Symmetry

Run east through the grassy ruins and past the hanging bodies until you reach Sester’s Gate. Enemies here are the same crop you have already fought in Mammon, so nothing new blocks the path.

The Harbinger running through the overgrown ruins on the path toward Sester's Gate — The overgrown ruins stretch you cross on the way to Sester’s Gate. Image: Cold Symmetry

Push through Sester’s Refuge and take the cave that leads into the snow. The screen picks up a frost vignette the moment you cross into the Conquered Temple, which is your confirmation you are in the right region.

Cross the Valley of the Revered, the frozen cemetery zone. Grab the Martyr’s Ash pickups as you pass them — they give Frost resistance, and the Frost Soldiers here freeze you in place if enough of their mace hits land. They are also weak to Burn damage.

Keep following the snowy cliff paths and drop down where the route descends. Along the way you can pull the Glimpse Stone tarstone from a stone chest and a Thawed Gland from another chest.

At the large multi-level structure, exit and go down the three flights of stairs. The Winterglass Lake Beacon is at the bottom. You will pass a chest pinned shut by stone hands just before it — leave that one, it opens after you have the crown.

Mornefrost Grave walkthrough: getting the Immaculate Crown

Selecting Enter/Cleanse Beacon drops you into Mornefrost Grave. The dungeon is built around one gimmick: a three-way split where two of the paths are physically held shut by hand statues, and the only way to move them is to fetch the crown first.

Descend into the grave and walk to the three-way split. The left and middle routes are blocked by the large hand statues, so take the path on the right.

The Harbinger walking through the arched entryway into the Mornefrost Grave dungeon — Heading through the archway into Mornefrost Grave after entering the Winterglass Lake Beacon. Image: Cold Symmetry

Inside the next area, turn right at the closed gate and kill the three Wraiths standing in the corridor. Once they are down, turn left past them to slip into the space behind the gate.

Follow the corridor and pick up the Immaculate Crown from the body lying under the large ribcage, beside the gate. The crown is a key item, so it goes straight into your inventory with no equipping needed.

Walk back through the passage. A hand statue right by the doorway pulls itself aside as you approach, uncovering a chest that was hidden behind it.

Opening the chest freed by a stone hand statue in an icy cavern in Mornefrost Grave — A chest opens once the Immaculate Crown pushes the stone hand guarding it out of the way. Image: Cold Symmetry

Continue to the end of the corridor for one more Wraith and a pile of Coins, then return to the gate and stand on the plate to open it. That loops you back to the three-way split.

With the crown on you, the statues blocking the other two routes now move. Take the left path first, clear the enemies, and collect the Coins in that room before committing to the boss.

Caged Grisha boss fight and the Fusillade Stone

The middle path leads to the Caged Grisha, the beacon’s boss. It leans almost entirely on huge sweeping slashes that hit hard enough to erase most of your health bar in a couple of connections, so trading blows is the fastest way to lose the fight.

Dodge the wide swings when you have the room. When a slash comes out too close to roll away from, use Perfect Guard and follow it with a Riposte — that is where the bulk of your damage will come from. Back off between its combos rather than squeezing in an extra hit.

Killing it awards the Fusillade Stone tarstone, confirmed by the New Tarstone Acquired prompt.

The New Tarstone Acquired prompt showing the Fusillade Stone after the Caged Grisha fight — The New Tarstone Acquired screen for the Fusillade Stone, dropped by the Caged Grisha. Image: Cold Symmetry

Cleansing the beacon and confirming it worked

After the Caged Grisha falls, interact with the corruption at the end of the arena and accept the Ovum. You will see the NEW OVUM FOUND prompt followed by BEACON CLEANSED, which is the confirmation the dungeon is finished — there is nothing else to trigger.

A cleansed beacon also stops being a bare respawn point. Alongside resting, you get Level Up with Gloom, Change Equipment for your Primary, Sidearm and Seal slots, Mether’s Pulse upgrades using Revered Gland or Synaptic Vessel, and Return to Marrow Keep for fast travel. Cleansing additionally clears the obstructions that were stopping you from interacting with loot in the area.

Note: If a hand statue still refuses to move, you have not collected the crown yet. It is a passive effect — the statues react to your presence only while the Immaculate Crown is in your inventory.

Mornefrost Grave rewards

Reward	How you get it
Immaculate Crown	On a body under the large ribcage, down the right-hand path
Fusillade Stone	Defeating the Caged Grisha on the middle path
Grisha Remnant x1	Boss drop
Glimpse x1	Clearing the dungeon
Ova x1	Cleansing the corruption at the beacon core

What the Immaculate Crown unlocks outside the dungeon

The crown’s description is short — “Unlocks secrets within the ice” — but it applies to the whole Conquered Temple, not just Mornefrost Grave. Any path or chest sealed by a giant stone hand will open once you walk up to it with the crown in hand, including the stone-hand chest just outside the Winterglass Lake Beacon that you had to skip on the way in.

Backtrack to that chest as soon as you leave the dungeon, then sweep the rest of the frozen region for the hands you walked past earlier. With the beacon cleansed you can also rest, level up and warp back to Marrow Keep from here, which makes Winterglass Lake the practical staging point for the rest of the Conquered Temple and the run toward Droeg, the Conquerer.