You're wandering around the foggy, distorted hills of Chalk Peak, your sanity meter is flickering, and you've got a quest log that won't stop nagging you about a girl named Mary. If you've been playing Once Human for more than an hour, you know the drill. Tasks in this game range from "kill five deer" to "find a needle in a haystack while the haystack is actively trying to melt your brain." The Unfinished Expedition Once Human side quest falls firmly into that second category. It’s one of those missions that feels like it should be simple—just go to the lighthouse, right?—but the level design and the way quest markers work in this game can make it a total headache.
Honestly, the hardest part isn't even the enemies. It's the navigation. Once Human loves to give you a general area and then leave you to stumble over debris until you find the one specific pixel you're supposed to interact with. For the Unfinished Expedition, you're heading to the Meyer's Market region, specifically the lighthouse area near the coast.
Finding the Lighthouse and Starting the Expedition
Most players pick this up while exploring the coastline or chatting with NPCs in Meyer's Market. The quest essentially tasks you with investigating a lighthouse that has seen better days. When you get there, the atmosphere shifts. It’s creepy. It’s quiet. You’re looking for a girl named Mary, but the game doesn't just put a giant neon sign over her head.
You need to head to the bottom of the lighthouse first. Don't bother climbing to the top immediately; you'll just waste your stamina. Look for the small shack or the base entrance. Inside, you're going to find a series of notes. These notes are the "bread and butter" of the Unfinished Expedition Once Human lore. They detail the descent into madness that most of the inhabitants of Nalcott seem to be experiencing.
The First Major Roadblock: The Documents
A lot of people get stuck because they find one document and think they're done. No. You need to find all the pieces of the journal to progress the quest stage. They are usually scattered on desks or tucked away in corners of the room at the base of the lighthouse. If your quest objective doesn't update, you've missed a page.
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Check under the stairs. Check the crates.
Once you have the documents, the quest pushes you toward a nearby house. This is where things get a bit more combat-heavy. You aren't just fighting regular Rosetta soldiers here; you're dealing with Deviants that can catch you off guard if you're under-leveled. Most players tackle this around level 20 to 25, but if you're running a glass cannon build, those Rosetta snipers will ruin your day faster than a server lag spike.
Why the Unfinished Expedition Quest Is So Frustrating
Let's talk about the "Search the Area" mechanic. It’s a circle on your map. A big, yellow, frustrating circle.
Inside this circle, you’re looking for a specific house where Mary might be hiding. The house is located slightly inland from the lighthouse itself. It looks like every other abandoned cottage in Chalk Peak, which is exactly the problem. You're looking for the one with the specific quest trigger near the front door.
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- Tip: Look for the house with the most "life" in it—usually indicated by more items you can scavenge.
- The house contains a letter from Mary’s father.
- You’ll also find a photo. Keep that. It’s a quest item you can’t drop.
Basically, the Unfinished Expedition Once Human mission is a scavenger hunt disguised as a rescue mission. You’re following a trail of breadcrumbs that are decades old. The environmental storytelling is actually pretty good if you stop to read the text, but let's be real: most of us just want the Energy Links and the EXP.
Combat and Survival in Chalk Peak
Chalk Peak is a step up in difficulty from the starting wetlands. The enemies in the Unfinished Expedition Once Human area are more aggressive. You’ll encounter Gluttons and maybe even a stray Elite if you wander too far off the path.
Keep your weapon durability in mind. There is nothing worse than getting to the final stage of a quest and having your primary crossbow or rifle break because you forgot to hit the repair bench at your territory.
Dealing with the Rosetta Soldiers
The Rosetta guys at the dig site nearby sometimes aggro onto you while you're doing this quest. They have decent aim. Use the environment. The lighthouse and the surrounding houses have plenty of "peek-a-boo" spots where you can take shots and duck back into cover. If you’re struggling, bring a sniper rifle. Taking them out from 100 meters away is much easier than trying to shotgun them in a cramped hallway.
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The Conclusion of Mary’s Story
After you find the final set of clues in the house, you have to return to a specific NPC to "finish" the expedition. Usually, this is Claire or another quest giver back at the main hub.
Wait.
Check your inventory. Make sure you actually picked up the "Small Box" or the "Old Photo." If you don't have those, the NPC won't talk to you. You'll have to run all the way back, which is a massive pain if you haven't unlocked the nearby teleportation towers yet.
The story ends on a bit of a somber note. Without spoiling too much, the "Unfinished" part of the title is very literal. It’s a reflection of the state of the world in Once Human—people trying to complete things that are already lost to the Stardust.
Actionable Steps for Your Next Session
If you’re currently staring at your map wondering where to go next for the Unfinished Expedition Once Human quest, do exactly this:
- Teleport to the Meyer's Market area and head south-west toward the coast of Chalk Peak.
- Clear the Lighthouse base first. Loot every single desk. If you don't see a "Quest Item Picked Up" notification, keep looking.
- Move to the house at coordinates roughly (around the 5000, -5000 range, but check your in-game map overlay for the yellow circle).
- Kill the Rosetta guards before you try to interact with the objects. Interacting with quest items locks you into an animation that makes you a sitting duck.
- Check the upstairs of the house. People always forget the second floor.
- Read the final letter. This triggers the quest completion flag.
- Fast travel back to the quest giver immediately to turn it in and claim your rewards.
Don't overthink the puzzles. In Once Human, if something looks like a clue, it probably is. If you're stuck, try using your "Q" scan (Spacetime) to highlight interactive objects in the room. This will often show you the glow of a document hidden under a chair or behind a crate that you'd otherwise never see.