The Underlab is your bonfire
The Underlab (some sources write it as “Under Labs”) is Mina’s base and safe room — the closest thing the game has to a bonfire. You reach it by burrowing into dirt mounds to dive underground. Once inside, it acts as Mina’s equip screen, letting you outfit her with weapons and trinkets, and it’s where you refill Plasma Vials, convert Bones to Bonestone, and respawn. One review compared trinkets here to the Pictos in Clair Obscur: Expedition 33 — equipment boons you slot in and out.
Equipping and swapping trinkets
Inside the Underlab you’ll find a Trinket Chest. This is where you equip, unequip and swap your trinket loadout — and you can do it freely, so the standard advice is to keep one set for exploration and another for boss fights and switch right before a fight. The chest can be sorted by Newest/Oldest, Most Used, or Offense/Defense to make finding the right trinket quick. See Best Trinkets & Builds for loadouts worth swapping to.
Saving and protecting your progress
Because the Underlab is your respawn point, it’s also where you lock in gains. Converting Bones to Bonestone banks them as safe, death-proof progress — unlike pocketed Bones, banked Bonestone survives death. Make a habit of banking before risky pushes (see Bones & Bone Up for the death penalty).
Fast travel: train stations and mirrors
Tenebrous Isle is non-linear, so getting around matters:
- Train stations form the fast-travel network. Unlocking a station costs Bones (around 10,000), and once open it lets you hop between regions instead of backtracking on foot.
- Mirrors — each region has one, and the six mirrors warp you to the Astral Orrery, tying the world together in a hub-and-spoke layout.
| Detail | Value |
|---|---|
| What it is | Your equip screen, safe room and respawn point |
| How you reach it | Burrow into dirt mounds to dive underground |
| What you do there | Swap weapons and trinkets, refill Plasma, convert Bones to Bonestone |
| Train stations | Fast-travel network (unlock cost around 10,000 Bones) |
| Mirrors | Six mirrors warp you to the Astral Orrery |
