Control Resonant: New Growth Quest Walkthrough (and Underhill Choice)

New Growth is a side story in Control Resonant that sends Dylan Faden after Dr. Raya Underhill, a missing Mold researcher, across The Park and the Oldest House. It runs through a rooftop base, a hidden sewer laboratory, and a hunt for three escaped test subjects before ending in a conversation where you decide her fate.

Quick answer: Talk to Busken at the FBC Base, gather Underhill’s documents and keys, reach her apartment, clear her sewer lab, kill Specimen A, B, and C for their samples, then return and pick any final dialogue option to complete the quest.

How to start New Growth

You can start New Growth while Zoe is giving her Briefing. Find her in the Watchtower and speak with her; she tells you about Dr. Raya Underhill, a Mold research team member who has gone missing. This adds the quest to your log with Ask Around About Underhill as the first objective.

Head to The Park and make your way to the FBC Base, which sits on the rooftops. Set a marker for The Park Checkpoint on the map, cross the Mold-infested streets, and use the transition tunnel to reach the zone. Activate the FBC Base fast travel door on the rooftop so you can return quickly later.

Navigating to the Park Zone — Open the Central 5 map and set your route toward The Park Checkpoint to reach the FBC Base. Shown at 00:10 in WoW Quests’s video. Image: Remedy Entertainment

Investigate Underhill’s last known location

Find Busken with the staff posted on the FBC Base rooftop and talk to him. He says Underhill headed for her research site farther inside The Park, changing your objective to Investigate Underhill’s Last Known Location.

Inquiring About Underhill — Busken points Dylan toward Underhill's research site further into The Park. Shown at 02:25 in WoW Quests’s video. Image: Remedy Entertainment

Head south across the rooftops toward the search area, fighting off the Mold enemies along the way. You are looking for a research post marked by FBC equipment at the top of a building.

Go through the files on the campsite desk to find the Level 6 Keycard and Underhill’s Resignation Letter. Pick up Underhill’s Hypothesis nearby, too. The keycard grants Executive Sector access, which you’ll need for the next step.

Picking up Underhill's Hypothesis — Underhill's Hypothesis sits on the campsite desk alongside the Level 6 Keycard and her resignation letter. Shown at 08:29 in Ditech Gaming’s video. Image: Remedy Entertainment

Search Underhill’s office in Central Executive

Fast travel to Oldest House: Central Executive. From your arrival point, head to the second locked office, which the Level 6 Keycard (Clearance 06) now opens.

Search the office and pick up Underhill’s Personal Notes, Underhill’s Research Notes, the Welcome Letter, and the Underhill’s Apartment Key. The apartment key is the item you actually need to progress.

Gathering Office Documents & Key — The Welcome Letter is one of several documents in the Clearance 06 office; the Apartment Key here is the key pickup. Shown at 10:46 in Ditech Gaming’s video. Image: Remedy Entertainment

Reach Underhill’s apartment and talk to her

Fast travel back to the FBC Base in The Park and follow the marker toward the apartment building. The route runs through rooftops and the orange Mold-filled sewer tunnels, so expect hostile Mold entities on the way.

Mold enemies are guarding the apartment entrance. Defeat them to gain access to the building, climb one level, then enter the apartment on your left.

Locating Underhill's Apartment — After clearing the Mold outside, head up a floor and take the residential corridor to Underhill's door on the left. Shown at 06:12 in WoW Quests’s video. Image: Remedy Entertainment

Dr. Underhill is near the kitchen. Speak with her about her connection to Casper Darling and her self-imposed exile. She asks you to recover her equipment and locate her escaped test subjects, and hands over the task. Grab the Key to Underhill’s Sewer Lab from the counter, plus Research Notes on the Mold from the desk inside.

Enter the sewer lab and collect the equipment

The lab entrance is in the sewer tunnels between the apartment and the FBC Base. Follow the marker to the underground door and use the key. Turn left inside to reach the laboratory.

Loot the ante-chamber container for Power Upgrade Point 3/3, then read the Response From Pope and The Mold Growth Stimulator documents on the desks.

Collecting Lab Documents — The Response From Pope note is one of the readable documents in the lab, near the equipment you need. Shown at 27:13 in Ditech Gaming’s video. Image: Remedy Entertainment

Take the Mold Growth Stimulator tool and all four Sample Tubes from the tables. Once equipped, drop over the railing to find the first test subject’s trail; your objective then changes to Track Down and Defeat the Test Subjects.

Find and defeat all three test subjects

When the tracking prompt shows up, activate it and stay on the Mold’s trail until it branches. You must find three specimens in all, and collect the Mold Sample Test Tube each one drops. Fire is highly effective against these Mold creatures, so use Inferno if your build includes it.

Specimen	Where to find it
Specimen A	Caged enclosure in the deep sewer cavern
Specimen B	Underground courtyard in the sewers
Specimen C	A back alley reached through the rooftops

Follow the first split to the left to reach one specimen, defeat it, and grab its sample. Return to the remaining trail, follow it toward The Park, and it splits again into two more routes. The order you clear those two does not matter. Once all three are dead and you hold every Mold Sample Test Tube, head back to Underhill.

Assist Mode’s one-hit kills option can trivialize the Specimen A fight if you enable it in the settings, though it is optional.

After the last specimen falls, Zoe calls over comms to say Emily Pope has ordered Underhill detained. Travel back through the sewers and park streets to the apartment.

The final choice with Dr. Underhill

The closing conversation gives you three ways to end things: report her to the FBC, let her leave without the samples, or hand her the samples with Take the samples. Selecting any of them completes New Growth.

The choice only affects what happens to Underhill herself. Report her and Dylan later learns the Bureau takes her away. Let her go, with or without the samples, and she walks free. None of these outcomes change the quest rewards, and there are no extra post-quest interactions tied to the decision, so pick whichever ending you prefer.

New Growth rewards and completion

You know the quest is finished when the final dialogue closes and New Growth clears from your active log. Completion awards the following:

Untapped Brass Dusters weapon mod (Artifact Recipe)
Talent Point +1
Power Upgrade Point 3/3 (picked up in the lab)
Budding Mycologist trophy/achievement

Because the ending choice has no effect on these rewards, you can complete New Growth however you like and still walk away with the full set.