New Growth Overview
The New Growth side story matters because it unlocks a Mold-focused investigation, leads to three dangerous specimens, and ends with a choice about Dr. Raya Underhill’s future. Completing it also contributes toward the Budding Mycologist Trophy or Achievement. The control resonant new growth quest is set primarily in The Park, with a required detour to Central Executive.
Underhill is an FBC Mold researcher who has disappeared from her team. Her records reveal that she has separated herself from Bureau oversight and is pursuing a more aggressive way to stop the Mold.
| Quest detail | Information |
|---|---|
| Quest type | Optional Side Story |
| Main area | The Park |
| Key character | Dr. Raya Underhill |
| Required destinations | FBC Base, Central Executive, Underhill’s apartment, sewer lab |
| Completion reward | Untapped Brass Dusters Artifact Recipe and Budding Mycologist Trophy/Achievement progress |
You can begin New Growth after progressing far enough through the story. It may start after completing Zoe’s Briefing and speaking with Zoe again, or by speaking directly to the FBC staff member on the FBC Base rooftop in The Park.
If the rooftop route is inconvenient, reach the base by restoring elevator power or by using the northeastern sewer route and approaching from the street east of the building.
Find Dr. Underhill
Start at the FBC Base Fast Travel Door in The Park. Speak with the nearby FBC guard, Busken, to learn that Underhill walked away from a research site and stopped responding to communications. Your next objective points south to her last known location.
Climb onto the small research rooftop and inspect the table. Pick up Underhill’s Resignation Letter and the Level 6 Clearance Keycard. The keycard opens the next lead in the Oldest House.
Fast Travel to Central Executive. Go upstairs and look for the Level 6 offices. Search the accessible rooms and collect the notes, welcome letter, and Underhill’s Apartment Key. These items establish where she went after leaving the Bureau.
| Objective | Where to go | What to collect or do |
|---|---|---|
| Ask about Underhill | FBC Base, The Park | Speak with Busken or the nearby FBC staff member |
| Investigate last location | South of the Fast Travel Door | Read the resignation letter and take the Level 6 keycard |
| Search her office | Central Executive | Open Level 6 rooms and find her apartment key |
| Locate Underhill | Upper Park residential building | Clear Mold enemies and enter her apartment |
Return to The Park and follow the marker to the apartment building. Mold enemies block the entrance, so defeat them before trying to enter. Go upstairs, then take the first door on the left. Underhill is near the kitchen area.
Talk through her dialogue before leaving. She explains that she has been growing test specimens in a sewer laboratory and needs samples from them. Before departing, take the key to Underhill’s Sewer Lab from the nearby counter or table. Missing this key is the most common reason the lab door remains locked.
Collect Equipment and Hunt the Test Subjects
The laboratory entrance is underground, between Underhill’s apartment area and the FBC Base. Enter the sewer system, take the left route at the junction, and unlock the laboratory door with Underhill’s key. Inside, interact with the equipment on the table to collect the testing gear.
The lab also contains supplies such as sample tubes and a Mold Growth Simulator. Once you are ready, move around the corner and drop down to the white Mold growth below. Interacting with it begins the specimen-tracking sequence.
The Mold does not simply mark the enemies immediately. Follow it as it moves through the sewer paths, rooftops, and streets. It periodically pauses so you can interact with it again, then eventually splits. Follow every branch until all three specimens are found and defeated.
| Test subject | General route | Useful note |
|---|---|---|
| Specimen A | First left branch in the sewer route | Usually the quickest target after the first split |
| Specimen B | Park-side route, then the left branch after reaching the surface | Requires following Mold across rooftops |
| Specimen C | Remaining Park-side branch | Farther from the split and easy to overlook |
The map helps here: look for a cloud-like Mold icon with an exclamation mark. If the trail seems to vanish, check above and below your current level. Several sections require climbing, jumping across debris, or using rooftop traversal instead of following the street.
Use the following route priorities to avoid backtracking:
- Follow the initial Mold trail until it first divides.
- Take the left branch first to reach Specimen A.
- Return to the split and follow the other trail out of the sewers.
- At the surface split, clear the closer left-side path for Specimen B.
- Return to the second split and follow the remaining right-side route to Specimen C.
- Return to Underhill only after the objective tracker confirms all three are defeated.
Each target becomes hostile when reached. Fire-based attacks are especially effective against the Mold specimens, so abilities such as Inferno can shorten the fights. Keep moving when the enemy attacks at close range, and clear smaller Mold threats before focusing on the specimen if the arena becomes crowded.
Underhill’s Choice, Rewards, and FAQ
After defeating all three test subjects, return to Underhill’s apartment. She examines the recovered samples, while the FBC’s concerns about her unsanctioned experiments become explicit. You can report her, let her leave without the samples, or allow her to keep the samples and continue her work.
The decision changes Underhill’s immediate outcome and dialogue, not the quest reward. Reporting her results in the FBC taking her into custody. Letting her go reflects trust in her plan to use Patterning against the Mold, though she cannot promise it will work.
| Final decision | Immediate result | Reward impact |
|---|---|---|
| Report Underhill | The FBC detains her | No change |
| Let her leave without samples | She departs without the recovered material | No change |
| Give her the samples | She continues her independent research | No change |
Regardless of your choice, finishing the conversation completes New Growth. You receive the Untapped Brass Dusters Artifact Recipe and progress toward, or unlock, the Budding Mycologist Trophy/Achievement. The trophy requirement also involves completing the Carbon Copy questline.
FAQ
How do I start the control resonant new growth quest?
Progress through the story until Zoe’s Briefing is available, then speak with Zoe again, or talk to the FBC staff member on the rooftop of the FBC Base in The Park.
Why can’t I open Underhill’s sewer lab?
Return to Underhill’s apartment and pick up the Sewer Lab Key near her after completing the conversation. The lab door cannot be opened without it.
Where is Dr. Underhill’s apartment?
It is in the upper-right residential section of The Park. Defeat the Mold enemies outside the building, go upstairs, and enter the first door on the left.
How many test subjects are there?
There are three: Specimen A, Specimen B, and Specimen C. Follow every branch of the moving white Mold trail to locate them.
Does the Underhill choice affect rewards?
No. Reporting her, releasing her without samples, or giving her the samples changes the scene’s outcome but does not change the quest rewards.
