Crimson Desert Scholastone Institute: How to Activate the Lock Device Switch

Chapter 4 of Crimson Desert drops you into the Scholastone Institute for the Gate to the Otherworld quest, where professor Octavius delivers a long presentation and then sends you off with a single vague instruction. The objective reads “Activate the lock device switch underground,” and the game never explains that it hides a nine-button logic puzzle behind a stone panel. The puzzle itself takes about ten seconds once you know the order.

Quick answer: Go underground beneath the dome, interact with the wall panel, then press the top-left, bottom-right, bottom-left, top-right, and center buttons in that order. All nine buttons light up, the panel slides down, and you pull the handle behind it.

Crimson Desert objective tracker reading Activate the lock device switch underground during Chapter 4 — The objective appears as soon as Octavius finishes his presentation at the Scholastone Institute. Image: Pearl Abyss

Where the lock device switch is at Scholastone Institute

The quest only starts in the afternoon. If you reach the domed plaza in front of the institute too early, use the time-skip prompt in the lower right corner to move the clock forward until Octavius begins speaking. The switch itself sits one level below the plaza, which is why the quest marker points straight down through the floor.

After the speech ends, walk counter-clockwise around the dome behind Octavius. Head for the northeast corner of the plaza, near the cube-shaped pillars that ring the experiment site.

Player crossing the Scholastone Institute plaza toward the underground path with the quest marker active — Cross the plaza and follow the marker toward the northeast corner. Image: Pearl Abyss

Take the lantern-lined pathway down. It leads to a staircase cut into the cliffside that drops into the chamber under the plaza. You can also vault the balustrade on the right and drop down the rocky path if you would rather skip the stairs.

Descending the stone steps underground with the yellow lock device marker visible ahead — The yellow marker sits below you during the descent to the underground chamber. Image: Pearl Abyss

At the bottom, bear left and look for the wall where a thick stone pipe runs up into the ceiling. The lock device is embedded just above that junction. It looks like a plain carved panel rather than a machine, and the interaction prompt labels it as a hatch.

Carved stone wall panel underground that hides the lock device switch puzzle — The lock device is the carved stone panel set into the wall beneath the pipe. Image: Pearl Abyss

Lock device switch puzzle solution

Interacting with the panel opens a 3×3 grid of buttons. The goal is simple to state and annoying to brute-force: every one of the nine buttons has to be pressed in and glowing at the same time. The catch is that pressing any button also flips every other button in its row and its column to the opposite state.

Move between buttons with the left stick or WASD, then press the confirm prompt to push one in. Five presses is the minimum needed from the default layout, and there is more than one valid five-press route.

Button grid puzzle open on the lock device with the press prompt shown on screen — The press prompt appears once the grid is open and a button is highlighted. Image: Pearl Abyss

Press	Corner-first route	Alternate route
1	Top-left	Top-middle
2	Bottom-right	Middle-left
3	Bottom-left	Top-left
4	Top-right	Bottom-right
5	Center	Center

The corner-first route is the easier one to remember, since order between the four corners does not matter as long as the center comes last. Both sequences also work mirrored or rotated, so a solution you work out on your own that hits the same shape will still finish in five presses.

How to reset the grid if the sequence stops working

Both sequences assume the grid is in its default starting layout. If you pressed a few buttons at random before looking up the answer, the pattern above will not land, because the toggles have already scrambled the board.

Back out of the puzzle with the cancel input, then interact with the panel again. That returns the grid to its original layout, and the five-press sequence works from there. The only two reasons the puzzle fails to open are a scrambled starting state and a grid where one button is still unlit.

Tip: count the glowing buttons before your final press. If eight are lit and one is dark, you are one toggle away rather than one press away, and resetting is faster than guessing.

Pulling the handle to confirm the switch is active

When all nine buttons glow at once, the stone panel slides down on its own and exposes a handle set into the wall behind it. Interact with the same spot again and use the operate prompt to pull it.

A cutscene plays as the machinery powers up and the dome above the plaza opens. That cutscene is your confirmation. If it does not trigger, you solved the grid but never pulled the handle, so step back to the wall and interact once more.

With the switch active, the objective updates to “Insert the batteries to activate the device” and you head back up to the plaza, either by the northeast stairs or by climbing through the newly opened dome. Four cube-shaped batteries sit beside the four pillars ringing the experiment, and the rest of the quest is powered ordnance and Octavius finding out exactly how badly an experiment can go.