Mask Puzzle Solution in Onimusha: Way of the Sword (Underground Level 2)

The mask puzzle is the roadblock that stops “What Lurks in the Shadows” cold. You reach a sealed door in the Underground Laboratory, the objective tells you to trigger its mechanism, and there is nothing in the room to pull, push, or hit. The answer is a shooting puzzle, and the reward locked behind it is the Unsettling Mask.

Quick answer: In the lantern-lit room on Underground Level 2, draw the Oni Bow at the masks mounted on busts along the back wall and shoot them one at a time in the correct order, beginning with the bottom-left red mask, then the top-left pale mask. When the sequence lands, the cage in the room springs open and drops the Unsettling Mask.

Where the mask puzzle is: Underground Laboratory, Underground Level 2

The puzzle sits inside Dokyo’s underground lab beneath the imperial castle in Kyoto, on the floor labelled Underground Level 2 on the map. The stage is built like a Japanese ghost house, and this particular room is dressed like a small theater, with red lanterns strung overhead and masks fixed to the walls.

You arrive here with the quest “What Lurks in the Shadows” active and the objective set to “Find a way to trigger the door’s mechanism.” The door itself is barred, and circling the room turns up no switch and no lever. That is intentional. The mechanism is not something you interact with by hand.

Musashi standing in front of the barred door on Underground Level 2 with the quest objective on screen — The barred doorway that ends the corridor on Underground Level 2, with the objective still asking you to trigger its mechanism. Image: CAPCOM

What you need before starting the mask puzzle

Requirement	Detail
Quest	“What Lurks in the Shadows” must be active
Location	Underground Laboratory, Underground Level 2
Equipment	Oni Bow (the masks can only be triggered by arrows)
Reward	Unsettling Mask, held in a cage in the room

The Oni Bow is the only tool that matters here. If you have not picked it up yet, the room will simply refuse to respond, no matter how long you spend looking for an interact prompt.

How to solve the mask puzzle with the Oni Bow

Open the map and confirm you are on Underground Level 2 rather than Underground Level 3. The two floors look similar and it is easy to wander down a level while hunting for the door mechanism.

Musashi approaching the sealed door during the What Lurks in the Shadows quest in the underground lab — Approaching the sealed door on Underground Level 2 during “What Lurks in the Shadows.” Image: CAPCOM

Follow the corridor to the set of sliding doors and step inside. The moment you enter the room with the red lanterns, the objective changes to “Solve the mask puzzle.”

Walk to the back wall, where five masks are mounted on busts. Shizuka will speak up about them, which is your cue that these are the targets rather than set dressing.

Musashi facing the wall of mounted masks as the objective updates to solve the mask puzzle — The objective switches to “Solve the mask puzzle” once you are in front of the mounted masks. Image: CAPCOM

Draw the Oni Bow and put your first arrow into the bottom-left mask, the red one. Take your time aiming; the busts are close together and a stray arrow into the wrong mask is the most common way this goes sideways.

Move your aim straight up and shoot the top-left mask, the pale one. Two masks down, and the sequence is now committed.

Drop back down to the bottom row for your third shot, then keep working through the remaining masks in the order the room’s own lighting points you toward. Each correct hit advances the mechanism a step.

Close view of the central mask mechanism in the underground lab room as Musashi lines up a shot — The central mask mechanism, which only reacts once the arrows land in the right order. Image: CAPCOM

Once the sequence completes, walk to the cage that has opened and take the Unsettling Mask. That item is what the whole room exists to hand you.

Where the shooting order comes from

The order is not written down anywhere and there is no note to collect. The clue is in the room’s construction. Light falls through decorative windows on one wall, and the way it lands is what tells you which mask to hit and when. If you have been staring at the busts and getting nowhere, leave the wall and look at the rest of the space instead.

Shizuka, the presence living inside Musashi’s Oni Gauntlet, also nudges you along if you stall. Her hints are gentle rather than a full solution, so treat them as a direction to look in, not an answer.

How to confirm the mask puzzle is solved

There are three signals, and they arrive together. The mechanism audibly triggers, the cage in the room opens, and the Unsettling Mask becomes collectable. Grabbing it clears the “Solve the mask puzzle” objective and lets “What Lurks in the Shadows” continue past the sealed door.

If nothing happens, the reason is almost always one of a short list. Check these before you assume the puzzle is bugged.

You are melee attacking or trying to interact with the masks instead of shooting them.
You do not have the Oni Bow equipped, so no arrow ever reaches a mask.
An arrow clipped the wrong mask, which breaks the sequence and means starting the order again.
You are searching for a switch or lever. There is none in this room.

Note: expect this to take a few minutes rather than a few seconds. Director Satoru Nihei has described these stage-based puzzles as deliberate pauses in the action, dropped into each stage to give players something to think about between fights, and the underground lab room is a clear example of that design at work.

It is also worth noting what this puzzle replaces. The sliding puzzle boxes that ran through Warlords, Samurai’s Destiny, Demon Siege, and Dawn of Dreams are gone entirely, and room-scale puzzles like this one have taken their place. Solve the masks, pocket the Unsettling Mask, and the door ahead opens the way it was always going to.