As you explore farther and farther into Mortal Shell’s world, you’ll spot stone frog-like statues to interact with. When you first encounter them (and for a long time after), you’ll get a “chest is locked” response when you attempt to open them.
In this guide, we’ll tell you how and when those chests will unlock.
While Mortal Shell is militantly obscure as a rule, you’ll slowly learn the game’s structure. Once you’ve explored Fallgrim and its surroundings, you’ll find three temples where you can collect three new weapons. Through those temples, you’ll find self-contained levels where you’ll face tough boss fight against a Revered.
When each boss is dead, you’ll collect a Sacred Gland. You must return these to the Old Prisoner in Fallgrim Tower to progress the game’s story.
More importantly, while you’re carrying a gland, all of those frog statue chests will be glowing orange and unlocked.
Thestus and the fog
When you collect your first gland, you’ll notice that the world looks a little different on your way back to Fallgrim. There will be a sickly gray-green fog everywhere and a new breed of enemy to face — those jumping scavengers.
Back at Fallgrim, a new NPC will have arrived. Upstairs near the weapons, you’ll meet Thestus, a cloaked figure with a lantern. From now on, paying Thestus Glimpses will bring or dismiss the fog (and those scavenger enemies). While the fog is active, the frog chests will be unlocked.
What do you get from them?
The chests don’t contain anything unique, but the items inside will be useful. You’ll find things like large stashes of Tar or Glimpses, or even Quenching Acid that you can use to upgrade any weapon.