The Mining Shaft Key is on a body on a side ledge partway along the Old Mine elevator shaft. Reach the elevator after redirecting the minecart through the blocked passage, then step off at the intermediate ledge instead of riding straight to the normal stop. Use the key at the locked door beside the minecart track switch.
The switch and the key perform different jobs. The switch redirects the cart so it breaks the obstruction; it does not unlock the nearby door or give you the key.
Reach the elevator beyond the minecart obstruction
Progress through the minecart tunnels in the Caverns’ Old Mine area until you reach the track-control switch. Redirect the minecart so it breaks through the blocked passage, then follow the opened route to the elevator connecting back toward the Old Mine Lantern.
You are looking for this elevator, rather than a key dropped by an enemy beside the rails. Keep the track-switch location in mind, because the door you need to unlock is back beside it.
Step off at the intermediate ledge
- Ride the elevator and watch the openings along the shaft as it moves.
- Look for the side ledge between the elevator’s normal stopping points.
- Step onto that ledge and search the body to collect the Mining Shaft Key.
If you arrive at the Old Mine Lantern without the key, you have gone past the intermediate pickup. Ride the elevator again and watch for the side opening. The useful landmark is the ledge along the shaft, not the elevator’s upper or lower destination.
Return to the locked door beside the switch
Go back to the control where you redirected the minecart. The locked door beside that switch accepts the Mining Shaft Key.
Open it and take the elevator beyond the door down into the lower shaft. This is a separate elevator from the one beside the key pickup. Finding the key does not require searching every lift in the Caverns: collect it from the intermediate ledge, then return to this specific door.
Optional healing upgrade beyond the door
Follow the platforms down through the shaft. A chest near a Volunteer contains a Ferrofluid Flask Power Upgrade.
This chest is a useful detour if you want stronger healing. It is not another key, and opening it should not be confused with the earlier act of unlocking the Mining Shaft door.
| Landmark | What it does |
|---|---|
| Minecart track switch | Changes the cart’s route to break the obstruction. |
| Body on the elevator’s middle ledge | Holds the Mining Shaft Key. |
| Locked door beside the track switch | Uses the key and leads to the lower-shaft elevator. |
| Chest farther down the shaft | Contains the optional Flask power upgrade. |
Related Caverns guides
- Complete Homesick near Last Sunlight.
- Follow The Oathbound’s investigation.
- Check the difference between Flask upgrades.
Source and verification
PowerPyx’s Chapter 4 collectible guide identifies the elevator ledge, the door beside the redirected-minecart switch and the healing upgrade beyond it. This page follows those published landmarks; it does not claim an independently tested jump timing or a precise coordinate for the ledge.