Clair Obscur: Expedition 33 – How to Complete the Demineur Quest (Choices & Rewards)

Here’s how to start and finish the Demineur quest in Clair Obscur: Expedition 33, where to find the Intact Mine, and what happens if you choose to fight instead.
🎨 Clair Obscur: Expedition 33 – Demineur Side Quest Guide
Clair Obscur: Expedition 33 is packed with emotional story beats and tough battles, but it also hides some surprisingly meaningful side quests. One of the earliest — and easiest to miss — is the Demineur quest, tucked away in the Flying Waters region.
If you’re not combing every nook and cranny, it’s easy to walk right past it. So here’s a full walkthrough on how to start and finish the quest, plus the consequences for each decision you can make.
🗺️ How to Start the Demineur Quest
To find the quest:
- Progress the story until you reach Flying Waters.
- After reuniting with Maelle and unlocking the Noco’s Hut rest point, keep moving forward until you reach a large open space.
- Instead of going straight, take the right-hand path.
- At the end of that path, look for a circular cave-like opening on your right.
- Inside, you’ll find a white Demineur NPC just standing there.

Unlike the aggressive Demineurs you’ve fought, this one is passive. Interact with it and you’ll get three choices:
- Examine
- Attack
- Let’s Leave It
Choosing Examine will reveal that it’s missing its Underwater Mine — kicking off your objective to find and return it.
💣 How to Find the Intact Mine
From the Demineur’s location, look around and you’ll see some nearby platforms.
Here’s how to reach the Intact Mine:
- Jump across the platforms until you reach a small clearing.
- Look south — you’ll see a faint purple glow in the distance.
- Jump onto the rock formation to the right and follow the path.
- After two more jumps, you’ll reach a glowing item — that’s the Intact Mine.
If you fall, don’t worry — there’s a climbable wall nearby that lets you get back up quickly.

🏆 Turn in the Mine – Quest Reward
Bring the Intact Mine back to the Demineur and interact with it again. After the scene, you’ll get:
- Deminerim (Level 3 Weapon for Lune)
At this point, you’ve technically completed the quest — but you still have the option to attack the Demineur and trigger a boss fight for extra loot.

⚔️ What Happens If You Attack the Demineur
If you choose to fight the Demineur — either immediately or after turning in the Mine — it becomes a mini-boss with a couple of interesting mechanics:
🧠 Boss Fight Details:
- If you already gave it the Intact Mine, you can target the Underwater Mine during the fight for a big damage spike. This also disables one of its main attacks.
- The Demineur is tougher than your usual enemy — with more health and stronger hits.
🌀 Moves to Watch For:
- Mine Swing: A slow, heavy attack. Parry or dodge it — or disable it by destroying the Mine early.
- Thunder Strike: Hits one party member. Listen for a pitch change in the sound cue to time your dodge.
⚡ Weakness: The Demineur is vulnerable to Electricity, so plan your skills and party setup around that.
🪙 Boss Fight Rewards:
- 3x Colour of Lumina
- 1x Chroma Catalyst
🎭 Which Path Should You Take?
If you’re focused on unlocking Lune’s gear, we recommend turning in the Mine first to get the Deminerim weapon — it’s one of the earlier rare weapon rewards.
But if you want to go full completionist, you can do both: complete the quest, then fight the Demineur anyway for the bonus loot. Just be ready for a tougher version of the enemy.
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- Clair Obscur: Expedition 33 – Sirene’s Dress Guide (How to Enter & All Rewards)
- How to Get the ‘Peace at Last’ Achievement in Clair Obscur: Expedition 33 (Simon Boss Guide)
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