Control Resonant Maintenance Protocol Door Code, Bulb Fixes, and Escape

QUICK ANSWER
Investigate the Oldest House Alarm, appease three marked bulbs, then escape the projector slide to finish Maintenance Protocol and earn the Standard Issue Coverall.

The Investigate the Oldest House Alarm objective leads Dylan to a locked entrance in Underpass.

Contents hide

Enter Underpass through the locked doors
How to finish Maintenance Protocol
Clear Underpass and activate the bulb coordinates
Reach Halfway Trail and appease the Volatile Bulb
Reach Research Stations and appease the Electrosensitive Bulb
Reach the flooded chamber and appease the Botanophobic Bulb
Return to the projector and escape the slides

Enter Underpass through the locked doors

Check the Underpass map for its fast-travel doors and quest marker, then follow the dark corridor to the security doors marked Door to ‘old’ Oldest House. Listen to Zoe on comms. If the dialogue offers a question about the sounds, ask her before using the intercom.

Don’t miss thisShort, short, longSend two short sounds, then one long through the intercomEntry needs Morse code for “in.” Enter Hmm Hmm Hmmmmmm to open the locked doors.

How to finish Maintenance Protocol

Follow the alarm objective into Underpass, repair the Volatile Bulb, Electrosensitive Bulb, and Botanophobic Bulb, and return to the projector for the final escape.

STEP 1/24

Enter Underpass through the locked doors

Follow the corridor to the locked security doors and speak with Zoe at the intercom.

STEP 2/24

Open the security doors

Activate the intercom and enter the sound sequence given above, then pass through the opened metal doors.

STEP 3/24

12%

Clear Underpass and reach the projector

Drop into the moss-covered chamber and defeat the infected creatures with melee attacks and kinetic strikes.

STEP 4/24

17%

Pass through the offices

Take the doorway across the chamber, continue through the carpeted offices, and pass the metal gate into the projector room.

STEP 5/24

21%

Activate the bulb coordinates

Watch the Maintenance Worker’s briefing, then use the switchboard in the adjoining control room.

STEP 6/24

25%

Reach Halfway Trail for the Volatile Bulb

Backtrack to the open vertical area, climb its wall fixtures and ledges, and use the upper fast-travel door for Halfway Trail.

STEP 7/24

29%

Approach the Volatile Bulb

Cross the raised stone structures, drop to the lower platform, and use the wall ledges over the chasm to reach the red-carpeted platform and hanging bulb.

STEP 8/24

33%

Handle the interruption

The initial interaction gives way to a sudden enemy wave on the platform; secure the area before continuing with the bulb.

STEP 9/24

38%

Reassure the Volatile Bulb

Use Talk to Lightbulb and the dialogue wheel to resume the conversation with a calming reply.

STEP 10/24

42%

Finish the Volatile Bulb

Once it settles, use Fix the Light Bulb to carry out the appeasement ritual.

STEP 11/24

46%

Reach Research Stations for the Electrosensitive Bulb

Return toward the fast-travel doorway, select Research Stations, and cross the hanging metal platforms and red wall-running surfaces.

STEP 12/24

50%

Search around the second bulb

Descend through the structural gaps to the bulb’s area and search the surrounding rooms.

STEP 13/24

54%

Cross to the remaining power sources

Use the platforms over the chasm to reach the other power cores.

STEP 14/24

58%

Finish the Electrosensitive Bulb

Return to the bulb after clearing its nearby power sources, then interact with it to complete the ritual.

STEP 15/24

62%

Reach the Botanophobic Bulb

Consult the map and follow the tracked route over stone columns and metal beams, down beside the ravine, and through the flooded fungal corridor.

STEP 16/24

67%

Finish the Botanophobic Bulb

Once the growth-filled chamber is clear, interact with the third bulb and complete the established ritual.

STEP 17/24

71%

Return toward the projector

Retrace the flooded route, climb the blocks to the upper platform, and take the fast-travel door to Deepest Underpass.

STEP 18/24

75%

Reenter the projector room

Follow the vertical shaft and red-carpeted chamber back to the projector room in Underpass 6.

STEP 19/24

79%

Touch the projection

Read the Maintenance Worker’s final instruction and interact with the projected cartoon to enter the slide.

STEP 20/24

83%

Continue through the cartoon

Progress through the Maintenance Worker’s illustrated conversation after Dylan is pulled into the monochrome projection.

STEP 21/24

88%

Speak with The Board

Under Escape the Slides, continue the cartoon conversation and speak to The Board.

STEP 22/24

92%

Leave the failed gap attempt behind

The attempted route through the gap does not release Dylan; turn your attention to the unstable bulb.

STEP 23/24

96%

Finish Maintenance Protocol

Follow the bulb-breaking instruction below, then look for the quest completion banner when Dylan returns to the projector room.

STEP 24/24

100%

Leave the projector room

Retrace the corridor once the quest is complete.

Clear Underpass and activate the bulb coordinates

The Mold-contaminated approach crosses the UNDERPASS 5 and UNDERPASS 6 zone banners. Collect talent point upgrades after clearing the chamber. A Talent Point +1 popup appears. Along the office route, the small table beside the stairs holds The Roots Of The Oldest House?; the neighboring office has On The Oldest House’s Form and a pickup labeled Power Upgrade Point 1/3. Edible Glob, Aberrant Cuts, and Fungal Growth are collectible pickups.

In the projector room, the cartoon Maintenance Worker explains the bulb appeasement ritual. The briefing changes your objective to Find the Light Bulb Coordinates. The nearby switchboard has green indicators for the three locations; using it adds Fix the Volatile Bulb, Fix the Electrosensitive Bulb, and Fix the Botanophobic Bulb to the tracker.

Don’t miss thisThree rightward twistsTwist each loose bulb right three times in its socketThis is the Maintenance Worker’s shared appeasement ritual. Apply it after meeting each bulb’s local condition.

Reach Halfway Trail and appease the Volatile Bulb

The red-carpeted platform leads to the Volatile Bulb. You can begin interacting with it before the encounter interrupts you. It may panic when threatened, but calming speech settles it once the area is safe. The dialogue wheel offers Stop worrying, You deserve to be fixed, and Let’s get this done; “You deserve to be fixed” is an available reassuring reply.

Don’t miss thisArea clearClear nearby hostiles before completing Volatile Bulb appeasementFlying enemies and the wave that interrupts the interaction keep the bulb frightened. Defeat the threats, then continue speaking to it.

QUICK WIN

You can also reach Halfway Trail by following the route there on foot.

Reach Research Stations and appease the Electrosensitive Bulb

The route from Research Stations passes hanging platforms, red wall-running surfaces, and gaps descending toward the bulb. Its surrounding rooms extend across the chasm, so search beyond the first set of lamps before returning to the fixture.

Don’t miss thisPower sources clearedRemove nearby batteries, generators, and other energy sourcesThe Electrosensitive Bulb rejects competing power. Take out the generator cells supplying nearby lamps and pull the remaining power cores before appeasing it.

Reach the flooded chamber and appease the Botanophobic Bulb

Water and luminous fungal clusters cover the platform ahead; the flooded corridor leads to the Botanophobic Bulb and an adjoining growth-filled room.

Don’t miss thisGrowth clearedRemove surrounding and adjoining-room growth before appeasing the bulbThis bulb rejects organic material. Destroy the fungal or plant growth and defeat plant enemies in the chamber, then perform the ritual.

With all three external bulbs appeased, the tracker changes to Complete the Final Step at the Projector Room.

Return to the projector and escape the slides

Back in the Underpass 6 projector room, the Maintenance Worker reveals one final bulb inside the projection. Touching the cartoon swaps Dylan’s place with the worker and traps Dylan in its monochrome world. Continue the conversation until you can speak with The Board. The bulb there is unstable, and trying the gap fails.

Don’t miss thisBreak the bulbChoose Break the bulb and shatter the unstable bulbDuring The Board conversation, choose Break the bulb, then take the crowbar and break the drawn bulb. Destroying it releases Dylan from the slide and back into the projector room.

The Quest Completed MAINTENANCE PROTOCOL banner and Standard Issue Coverall outfit popup mark the finish. The old alarm in the Oldest House stops. Dylan leaves the projector room and returns to the corridor.

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