Mortal Shell 2: Thief’s Stone Location and Warp Attack Speed Effect

The Thief’s Stone is one of the few Tarstones in Mortal Shell 2 that changes how fast you swing rather than how hard you hit. Every melee strike you land feeds it, and the payoff is Warp, a buff that pushes your weapon attack speed up the longer you stay glued to a target. It is not sitting in a chest, though. You have to earn it in a trial arena tucked away in the cold northern stretch of the map.

Quick answer: Travel to the Vestige of Infinity, northeast of the Gate of Infinity beacon, activate the Corrupted Statue at the center of the flooded platform, clear both waves of enemies, then interact with the cleansed monolith to receive the Thief’s Stone.

Thief’s Stone location: Vestige of Infinity

The stone sits on a circular arena labeled Vestige of Infinity. On the map it reads as the platform opposite the statue where Ruk stands with the Map Fragment, northeast of the Gate of Infinity beacon. A central monolith rises out of a shallow pool in the middle of the ring, and that monolith is the Corrupted Statue you need to cleanse.

The closest fast travel point is The Silent Steps beacon. If you have already lit it, you can be standing at the trial in under a minute. If you have not, you will need to walk the beacon chain up from the south first.

Beacon	Role in the route
Outskirts of Mammon	Southern starting point if you are opening the path for the first time
Castigator’s Keep	First checkpoint along the way north
Barren Crest	Snowy cliff section, second checkpoint
The Silent Steps	Final beacon; the trial is a short run from here
Gate of Infinity	Map anchor for the Vestige of Infinity platform to the northeast

Route to the trial from The Silent Steps beacon

Rest at The Silent Steps beacon and head forward into the rocky cavern tunnel in front of you. Drop down into the lower passage and follow it straight through; there are no branching paths worth taking here.

Player character running along a rocky grass path with the combat HUD visible — The approach to the northern beacons runs through open cliff paths before the snow starts. Image: Cold Symmetry

Exit the tunnel and cross the narrow stone bridges built into the cliffside. The beams are thin and the drop is fatal, so walk the tight sections instead of sprinting them.

Player running forward through a narrow snow-covered rock passage — The snowy passages between Barren Crest and The Silent Steps. Image: Cold Symmetry

Take the leap across the rock gap and keep to the upper path. Enemies patrol this stretch, and you can run past most of them if you are only here for the Tarstone.

Reward notifications for Gloom, Galvanic Shard, and Coin appearing during a fight in a snowy ruin — Killing the enemies along the route drops Gloom, Galvanic Shards, and Coin. Image: Cold Symmetry

Cross the high ruined walkway at the end of the path. It opens directly into the pillared chamber that holds the Vestige of Infinity arena.

Armored character sprinting across a snow-covered open arena toward the trial site — The final open stretch before the Vestige of Infinity platform. Image: Cold Symmetry

Clear the Corrupted Statue trial and claim the reward

Climb the stairs to the shallow pool and walk up to the monolith until the Begin Trial prompt appears. Heal and refill your consumables before you press it, because the arena seals once the fight starts.

Fight through both waves. Skeletal enemies spawn around the outer edge of the pool and close in on the pillar, so keep circling rather than backing into the water at the center where you can get surrounded.

Once the last enemy drops, interact with the monolith again to cleanse it. You will see the New Tarstone Acquired: Thief’s Stone notification, along with Coin and crafting materials.

To confirm it worked, open the Tarstones menu. The Thief’s Stone should be listed as a Combat Tarstone at Level 1 with the description “Striking foes grants you Warp.” If the notification did not fire, the statue was not cleansed, which almost always means one enemy from the second wave is still alive somewhere on the platform.

Tarstones menu with Thief's Stone selected, showing its level, XP bar, and Warp stack description — The Thief’s Stone entry in the Tarstones menu, showing its level, XP progress, and Warp stack text. Image: Cold Symmetry

What Warp does and which weapons accept the stone

Warp is a stacking buff that slightly increases weapon attack speed. Each melee strike you land adds stacks, so the buff builds while you are pressuring a target and falls off when you disengage. That makes the Thief’s Stone strongest on fast, multi-hit weapons and on drawn-out boss fights where you can sustain a chain of hits.

It slots into your primary weapon, and it is only compatible with eight of them. You can have two Combat Tarstones equipped at once, so it pairs with a second combat effect rather than replacing one.

Compatible weapons
Axatana
Axe and Dagger
Black Needle
Clockwork Scythe
Great Martyr’s Blade
Obsidian Hammer
The Iconoclast
Veteran’s Battle Axe

Thief’s Stone upgrade levels and Warp stacks

Leveling the stone raises how many Warp stacks each strike grants, which is what actually pushes your attack speed toward its ceiling. The top level grants 3 Warp stacks per strike.

Level	Effect
Level 1	Striking foes grants you Warp
Level 2	Gain 1 Warp stack per strike
Level 3	Gain 2 Warp stacks per strike
Level 4	Gain 3 Warp stacks per strike

Upgrades happen at the Tarforge in Marrow Keep, but Franz cannot perform them until you hand him the Etching Needle. That quest item is in a chest just before the Magdalena, the Lady of the Woods boss fight. When you spot Ruk past the bridge, drop down through the opening and turn right before the tunnel to find a small alcove with a bone chest.

After Franz has the needle, the Thief’s Stone still has to earn it. Equip it and kill enemies to fill its XP bar, then return to Franz and pay Coin for each level. Note that the Tarstone’s description text updates as it levels, so check the stack count in the Tarforge screen before you spend.

Because the trial is repeatable content only in the sense that it stays available in free roam, there is no rush to grab it early. The stone is not missable, and you can pick it up after the final boss before rolling into New Game+ if the northern route is too rough on your current build.