Cog in the Wheel is an early side mission in Arknights: Endfield, sitting inside Valley IV under the “The Hub” section of the quest list. It is grouped with other operational errands such as Rumors about Tech, Had to Be Done, The Road is Rough, Alluvial Cleaning, AIC Manager, and Morale Booster.
While the exact in-mission objectives vary with your story progress and choices, its place in the structure of Valley IV is fixed. Understanding that structure helps you know when to expect Cog in the Wheel to show up and what you need to have done first.
Where Cog in the Wheel sits in the mission list
Arknights: Endfield divides content into three broad mission types: Main Missions, Side Missions, and Exploration Missions. Valley IV is one of the earliest open regions, and its local tasks are broken down by sub‑area. Under Region 1: Valley IV → The Hub, the mission list runs in this order:
- Rumors about Tech
- Had to Be Done
- The Road is Rough
- Alluvial Cleaning
- AIC Manager
- Morale Booster
- Cog in the Wheel
Cog in the Wheel is therefore not a starter quest. It appears after you have already spent some time stabilising The Hub, cleaning up the surrounding area, and interacting with the local AIC systems and morale‑related errands.
What you must complete before Cog in the Wheel
The mission ordering inside The Hub is a reliable indicator of prerequisites. To reach Cog in the Wheel, plan around clearing the earlier tasks in this sub‑region first.
Step 1: Progress the main story through Valley IV. Main Missions, such as Break the Siege, Valley Reboot, Rally and Unite, Westward into the Vale, Secure Sanctuary, and Building an Outpost, establish your first base and unlock The Hub as a functioning operations center. Play normally until The Hub and its side‑mission board are available.
Step 2: Finish the earlier Hub errands. Work through Rumors about Tech, Had to Be Done, The Road is Rough, Alluvial Cleaning, AIC Manager, and Morale Booster in whatever order the game surfaces them. These lay the groundwork for local infrastructure, data collection, and workforce support, which in turn sets up the context for Cog in the Wheel.
Step 3: Keep exploring Valley IV’s core area. Many Hub missions are tied to simple exploration triggers and resource nodes around Valley IV. As you fill in the local map, clear points of interest, and interact with terminals and NPCs clustered near the base, you naturally unlock the next items in The Hub’s list until Cog in the Wheel becomes available.
How Cog in the Wheel relates to other Valley IV missions
Valley IV’s missions are spread across several named sub‑regions besides The Hub: Valley Pass, Aburrey Quarry, Power Plateau, Origin Lodespring, and Originium Science Park. Each of those areas has its own short chain of side content, for example:
- Valley Pass with tasks like Where Are Thou My Love and OD Project: Refugee Camp I.
- Aburrey Quarry with Quarry Rescue and Fix the Super Crane.
- Power Plateau with Outpost: Reconstruction HQ and Lone Wolf.
- Origin Lodespring and Originium Science Park, each with their own sets of rescue, repair, and outpost‑focused missions.
Cog in the Wheel is part of the Hub‑centric line, not those satellite areas. You do not need to grind out every mission in Valley Pass or Aburrey Quarry to see it, but moving the main story forward and keeping up with Hub missions ensures it appears in a timely way.
Ensuring you can access Cog in the Wheel
Because Arknights: Endfield is structured around both combat and base‑building, some missions only become available once the operational side has reached a certain point. If Cog in the Wheel has not yet appeared in your list under The Hub, the most reliable actions are:
Step 1: Confirm that “Valley Reboot” is complete. Codes redemption and several broader features, including consistent side‑mission flow, only unlock once this early Chapter 1 mission is finished. If you have not yet passed that point, continue the Main Missions first.
Step 2: Return to OMV Dijiang and complete its initial side tasks. Hub‑level missions like Dijiang Upgrade and Maintenance I, Etchspace Salvage, and Echoes of Then help your overall infrastructure and can be tied, indirectly, to when certain region‑level errands populate.
Step 3: Interact with mission boards and terminals at The Hub. Some side missions are offered directly through local interfaces rather than as automatic pop‑ups. When you check in after major story beats, new entries for The Hub, including Cog in the Wheel, can appear.
Once Cog in the Wheel is unlocked in your Valley IV → The Hub list, treat it as part of the early stabilisation layer of Arknights: Endfield. Clearing it, alongside its neighboring errands, helps bring the region’s logistics and support network in line with the main story’s push deeper into Talos‑II.
