Key Takeaways
- Carbon Copy is a three-part side quest set in The Park, following twin sisters Heidi and Hannah Garrett across all three chapters.
- The quest starts by speaking to Heidi near the East Supply Route Station in The Park — but you must have started the New Growth side quest first.
- Part I — Find Hannah in her apartment south of Heidi’s shelter and report back for the Untapped Mother’s Locket.
- Part II — Speak to Dr. Florez at the Central Field Hospital, find Heidi’s note in the ER Medical Unit, then locate Heidi’s body in The Park apartment.
- Part III — Follow the trail of Hannah copies through The Park to the factory, defeat Mold Hannah, and earn the Untapped Medical Alert Bands and the Budding Mycologist trophy/achievement.
Carbon Copy is one of Control Resonant’s most emotionally charged side quests. What starts as a simple welfare check on a missing sister slowly unravels into something much darker, across three separate parts spread throughout the game. This guide covers every objective in order, so you can finish the full questline without getting stuck.
Carbon Copy Quest Overview
- Zone: The Park (all three parts)
- Requirement: Have started the New Growth side quest
- Parts: 3 (Carbon Copy, Part II, Part III)
- Final reward: Untapped Medical Alert Bands + Budding Mycologist trophy/achievement
Completing New Growth alongside the full Carbon Copy chain is required to unlock the Budding Mycologist trophy. Do not skip either questline if you are going for the platinum or 100% completion.
Carbon Copy Part I – Find Heidi’s Twin Sister
How to Start Carbon Copy
Head into The Park and look near the East Supply Route Station. Heidi is sheltering inside an elevated, lit concrete structure ringed by blue crystalline mold in the northernmost section of The Park. Drop into the building and make your way to the back to find her.
Speak with Heidi. She explains that her identical twin sister Hannah is somewhere in the apartment south of her shelter, and she refuses to evacuate without knowing Hannah is safe. She hands you Heidi’s Old Apartment Key and the quest begins, with the objective: Find Heidi’s Twin Sister in the Park.
Reach Hannah’s Apartment
From Heidi’s shelter, head south across the mold-covered rooftops. The mold formations act as natural bridges between buildings, so use them to cross the gaps. Watch for glowing, airborne mold enemies that patrol the rooftops and fire projectiles — clear them out as you move.
Follow the mold formations toward the building marked with an ASCE sign. Once you find the apartment building, use Heidi’s Old Apartment Key to open the door. Head through the living area — stop to pick up the readable note called Letter To Hannah from the coffee table — then continue into the back bedroom.
You will find Hannah sitting in a chair by the window. Speak with her, let her know help is coming and that the FBC evacuation team will get them both out safely. This updates your objective to Return to Heidi.
Return to Heidi
Cross the rooftops back to Heidi’s shelter and speak with her a second time. Tell her that Hannah is alive and waiting for evacuation. The quest completes and you receive the Untapped Mother’s Locket artifact.
As with every Untapped item in the game, the Locket does nothing while it sits in your inventory — equip it to activate its passive modifier. For a full breakdown of how these work, check the Control Resonant all artifacts guide.
Part I Reward
- Untapped Mother’s Locket (Artifact)
Carbon Copy Part II – Search for Clues to Find Heidi
How to Unlock Part II
Part II does not appear immediately. You need to complete Act 1 of the main story first — specifically the Enemy of My Enemy mission. Once that is done and you return to the game world, Zoe will contact Dylan by radio, and Part II will be added to your quest log automatically.
You also need a Level 1 Keycard to access certain FBC clearance doors during this part. If you do not have one yet, see the keycard guide for help.
Talk to Dr. Florez at the Field Hospital
Your first objective is to speak with Dr. Florez. Head to the Field Hospital in Central and find her at her outdoor workstation — there is a yellow diamond quest marker directly above her. Work through the full conversation. She explains that Hannah has become non-responsive and that Heidi has gone missing since being brought in.
Search the ER Medical Unit for Clues
The clues you need are in and around the ER Medical Unit, which is the container just below the main Field Hospital trailer. Before going inside, grab the collectible document called Notes on Pattern Victims from the gurney outside.
Enter the ER Medical Unit and read Medical Report: Hannah Garrett on the counter, then find and read the Note From Heidi inside the same unit. That note updates your objective: Return to Heidi and Hannah’s Apartment.
Return to the Sisters’ Apartment in The Park
Fast travel to The Park and make your way back to the apartment from Part I. Head upstairs and check the bathroom — you will find Heidi’s body. Use the Report Dead Body interaction, which triggers Dylan to contact Zoe and report what happened.
That call completes Carbon Copy: Part II. No reward is listed for this part — it is a story bridge into Part III, which begins immediately.
Carbon Copy Part III – Follow the Trail and Defeat Mold Hannah
How Part III Starts
Part III kicks off right as you exit Heidi and Hannah’s apartment after completing Part II. Check the rooftop above the apartment — you will see a row of identical, motionless Hannah copies standing in a line. Following them is your next objective.
Follow the Trail of Hannahs
The trail of copies leads through The Park district. Follow the line of figures south through the streets. You will need to navigate past mold enemies along the way, so stay alert. Key navigation points:
- Jump over the wall of Mold and head straight down the street ahead.
- At the end of the street, turn right and head down toward the parking garage. One of the copies will be visible outside, looking up at it.
- Head through the parking garage to the other side, then turn left.
- You will eventually see a large group of clones gathered outside a factory building with a Power Core Station nearby. This is your destination.
Outside the factory door, you will find Heidi standing and waiting. Speak with her before heading inside.
Try to Save Hannah / Defeat Mold Hannah
Enter the factory and head inside. Hannah is there — but she has been fully transformed by the Mold. The objective changes to Defeat Hannah.
Mold Hannah is a mini-boss fight. She hits hard and uses mold-based attacks, so keep moving and use your strongest damage output. Fire-based abilities (Ignite or Inferno, earned from the Deserter Resonant fight) deal bonus damage to Mold enemies, so if you have them equipped, this fight becomes significantly easier. For a refresher on which abilities work best in fights like this, check the Collective boss guide — many of the same combat tips apply here.
Once Hannah is defeated, head back outside to the alley where Heidi is standing. Speak with her and tell her about Hannah’s fate. This final conversation completes the Carbon Copy questline.
Part III Rewards
- Untapped Medical Alert Bands (Artifact)
- Budding Mycologist trophy/achievement (requires New Growth to also be completed)
Budding Mycologist Trophy – What You Need
The Budding Mycologist trophy unlocks when you deal with the major Mold incidents in Manhattan. In practice, that means completing both of these:
- Carbon Copy (all three parts)
- New Growth (the Underhill questline in The Park)
If you finish Carbon Copy Part III but the trophy does not pop, check your quest log — New Growth is almost certainly still in progress. You do not need to finish the full Park Resonant for this trophy, only those two side quest chains.
All Carbon Copy Rewards at a Glance
- Part I: Untapped Mother’s Locket (Artifact)
- Part II: No item reward — story progression only
- Part III: Untapped Medical Alert Bands (Artifact) + Budding Mycologist trophy
Tips for the Carbon Copy Questline
- Start New Growth at the same time. Both quests are set in The Park and share the same zone. Running them in parallel saves a lot of fast travel time and ensures the Budding Mycologist trophy does not slip through the cracks.
- Part II does not unlock right away. Do not waste time looking for it in your quest log immediately after Part I. Complete Act 1 and wait for Zoe’s radio call to trigger it.
- Bring fire abilities to Mold Hannah. Ignite and Inferno deal bonus damage to Mold-type enemies. If you have them, equip one before entering the factory.
- Finish the conversation with Heidi after the fight. The quest will stay open even after defeating Mold Hannah if you do not talk to Heidi outside the factory. Walk back out and speak with her to close it.
More Control Resonant Guides
If you are working through the full Park questlines or looking for more help, these guides have you covered:
- Into the Valley of Death Walkthrough — another side quest requiring careful navigation through a confusing zone
- Should You Turn In Dr. Underhill? (New Growth) — the key decision that pairs with Carbon Copy
- The Collective Boss Guide — The Park’s Resonant boss fight
- Unsupervised Science – All Experiments
- All Bosses and Where to Find Them
- All Artifacts Guide
- Control Resonant Codes – All Working Codes & How to Redeem Them
