The short answer
- How many keys
- Five, not four: Sapphire and Emerald inside Obmuer Temple, Ruby from breaking the Trident weapon, Amethyst from Umbada’s shop and Onyx from the boss of the Petrified Garden.
- What they open
- The three-key gate in Obmuer Temple (the Engraved Halberd), a hidden three-key door on the starting island, and the five-statue puzzle in the Petrified Garden.
- The Trident
- At the statue outside the Obmuer Temple door. Hit enemies with it until weapon level 5 and its head breaks off as the Ruby key.
- Needed to finish?
- Only Sapphire and Emerald, for the temple route. The other three are optional for the main story, but the fourth ending needs all five, because the skull door under the Petrified Garden sits behind the five-statue puzzle. Keys can be pulled out of a lock and reused.
- 5
- Trident keys
- 2
- Inside the temple
- Lv 5
- Trident breaks
- 15
- Coins for Amethyst
- 6 min
- Read time
- Nov 2026
- Checked on

All five trident keys and where each one is
In the order most players get them. The temple is the water dungeon you open with the four triangular slates; our progression route guide covers the slates and the route around it.
| Key | Where | What it opens first |
|---|---|---|
| Sapphire | Wall of the first flooded cavern in Obmuer Temple, by your landing spot | The one-lock door on the left of that cavern |
| Emerald | Rocks at the top of a staircase past the third Wind Gem | The grate to the Sacred Cistern crystal monument |
| Ruby | The Trident’s head, at weapon level 5 | Nothing on its own; the third key for the halberd gate |
| Amethyst | Umbada’s Trading Outpost, 15 Ancient Coins | The alternative third key |
| Onyx | Dropped by the Pale Whale, the Petrified Garden boss | The fifth statue in the Petrified Garden |
Sapphire: the first flooded cavern
From the first crystal monument inside the temple, go down to the explorer’s note by the ledge with flowing water and drop. Five or six Glaucusions swim below, so clear them before you search. The key is set into the wall near where you land. Across the cavern are two doors: the left takes one key, the right takes three. Use Sapphire on the left one.
Emerald: past the third Wind Gem
Save at the crystal monument behind the Sapphire door first, because getting back is a long trip. At the big pit, look down for two round openings and Wind Dash into the open one on the left. A toxic Homopiscium and two more come out of the water as you land. Follow the path to a staircase, beat the Skeletal Soldiers and crossbowmen who appear at the top, then check the rocks nearby. The key blends into the stone. It opens the grate at the end of that passage, which leads to the Sacred Cistern crystal monument.
Ruby: break the Trident
Covered in full below. It is the earliest optional key and usually your third.
Amethyst: Umbada’s Golden Duck stock
Umbada’s shop opens from any crystal monument once the Shrine Guardian gives you the Stone Duck Figurine. Each figurine you hand her adds stock. The Silver Duck from Dagoom does not add the key. Beat the Tower of Knowledge boss, bring her the Golden Duck Figurine, and the Amethyst key appears for 15 Ancient Coins. If you already have Ruby, it can wait.
Onyx: the Petrified Garden boss
The Petrified Garden is a hidden island. Fast travel to a warp station and jump off the platform during the teleport animation; the game’s own hint note calls it a leap of faith. Reaching the boss needs four Wind Dashes, or three plus the Cestus uppercut as an extra jump (Umbada sells the Cestus for 20 coins). Players report the Pale Whale drops the Onyx key. Beat it before you try the statue puzzle, which needs all five keys.

The Trident breaks into the Ruby key at weapon level 5
The Trident sits at the base of a statue on the flooded approach to Obmuer Temple, beside the door that takes the four triangular slates. You need two Wind Dashes in a row to cross the ruins, then a climb up a stone ramp out of the water past a Barnacle and skeletal guards. No key is needed to take it. Grab it before you enter the temple.
It is a Pierce weapon with 8 Power at average speed, and its secondary is a backward-dashing stab, the same move as the Rusted Spear. Equip it as your main weapon and fight with it. Only hits on enemies earn its experience; there is no switch or hidden trigger. At level 5 the loose head comes off and becomes the Ruby key, and the Trident is gone. Players report a bottle of Spirit Oil breaks it on the spot, but Spirit Oil is better spent on a weapon that evolves.
Three keys open the Engraved Halberd gate in Obmuer Temple
The trident puzzle most players hit first is the three-lock door on the right of the first flooded cavern, next to the Sapphire door. It looks like a progression block, and it is not. Put three keys in it at once and it opens to a chest with the Engraved Halberd, an 11 Power weapon that does both Pierce and Slash damage. It does not evolve.
The trick is that keys come back out. Once Sapphire and Emerald have opened their doors, interact with those locks to take them back, then pair them with Ruby or Amethyst. Two keys from inside the temple plus the Trident’s head is the earliest way in, well before the shop key exists.
The save point room past the pit also has trident keyholes. Players report one optional chamber with three keyholes at its entrance and two more farther in. None of them are needed for the three Royal Guards or the Dagoom boss door.
The hidden door on the starting island
Players report a second three-key door back on Neasied, hidden in the bushes near the well and the shortcut door to the starting campsite, with a further two-key room behind it. Its reward is not documented yet, so check it once you hold three keys.
The Petrified Garden statue puzzle takes all five keys by colour
The Garden has five petrified monster statues, each with a coloured gem. Place the key that matches the gem on each statue:
| Statue | Gem | Key |
|---|---|---|
| Ratty Bug | Purple | Amethyst |
| Slime | Blue | Sapphire |
| Bat | Green | Emerald |
| Deer (stag) | Black | Onyx |
| Homopiscium (fishman) | Red | Ruby |
Matching statues appear around the world as hints. The Ratty Bug is on the Isle of Neasied, and players place the Bat in the big red-water room of Deimpo Mausoleum. Once all five keys are in, the petrified enemies wake up and fight, and new doors open to loot. Some statues attack the instant they wake, so go in with full healing.
Mistakes with trident keys
- Mistake: Searching the temple for a third key. Fix: Only Sapphire and Emerald are inside. The third comes from the Trident.
- Mistake: Leaving keys in opened doors. Fix: Take them back out. The halberd gate needs three at the same time.
- Mistake: Expecting the Silver Duck to unlock the Amethyst key. Fix: It takes the Golden Duck, after the Tower of Knowledge boss.
- Mistake: Trying the Garden puzzle with four keys. Fix: Beat the Pale Whale for Onyx first.
FAQ
How many trident keys are in Queen’s Domain?
Five: Sapphire, Emerald, Ruby, Amethyst and Onyx. Only Sapphire and Emerald are needed to finish Obmuer Temple.
Where is the Trident weapon?
At the base of a statue on the flooded approach outside Obmuer Temple, next to the triangular slate door. Two Wind Dashes get you there.
How do I get a trident key from the Trident?
Fight with it until it reaches weapon level 5. Only hits on enemies count. The head breaks off as the Ruby key.
What is behind the three-key trident door?
The Engraved Halberd, an 11 Power Pierce and Slash weapon, in a chest behind the gate in the first flooded cavern.
Where do I buy the Amethyst trident key?
From Umbada for 15 Ancient Coins, after you give her the Golden Duck Figurine from the Tower of Knowledge boss.
Where is the fifth trident key?
The Onyx key is reported to drop from the Pale Whale, the boss on the hidden Petrified Garden island, reached by jumping off a warp station during the teleport animation.
Checklist
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Source & credit
Queen’s Domain is developed by Freshly Baked Games and published by Future Friends Games. Key locations were cross-checked against several player walkthroughs and the game’s Steam community discussions; details only one player has reported are marked as such. Screenshots are from the official Steam store page.




