Author note: Written by Jachin, a 23-year Resident Evil series fan based in Seoul, South Korea. This guide is based on 6 full RE9 playthroughs on PS5 and Steam (Casual → Insanity → NG+ Insanity completions). All strategies, timings, and locations have been personally tested across the v1.02 patch. AI tools were used only for grammar review and note organization; no AI-generated content appears in strategy analysis.
Verified on: v1.02 + DLC patch · Last reviewed: May 30, 2026 · About the author · Editorial policies
Plant 43 is not a plant — it’s a mold-based bioweapon. Created at ARK Facility in 2018 from research into Eveline’s E-virus strain. Marcus Halverson’s exposure protocol is what transformed him into Chunk. This is the complete biology + origin breakdown.
| When | Event |
|---|---|
| 2016 ARK Facility research | ARK Facility commissioned by The Connections. Initial mandate: study Eveline’s E-virus mold strain for therapeutic applications. |
| 2018 Plant 43 creation | Plant 43 designated as the modified E-virus mold variant. Originally synthesized for fast-spreading wound treatment. |
| 2019 first incidents | Plant 43 contained breach. 3 lab technicians infected. Quick suppression. Records sealed. |
| 2021 weaponization decision | ARK leadership pivots Plant 43 from medical to military application. Marcus Halverson assigned to safety review. |
| 2023 Lily’s diagnosis | Marcus discovers his daughter has leukemia. He proposes Plant 43 reverse-engineering for treatment. Rejected. |
| 2024 Marcus self-experimentation | Marcus injects himself with Plant 43 culture. 14-month transformation begins. Becomes “Chunk.” |
| 2026 RE9 events | Grace encounters Plant 43 as boss. Defeats core via Clatter Carbine bursts. Insanity-only audio reveals Marcus story. |
| Biology | Plant 43 is a fungal organism with mycelium network. Spreads via spores (8-second DoT damage). Roots form sensing structures. Plant 43 vs Eveline’s mold = same family, different strain. |
This lore decode reveals layers of RE9 most players miss. Cross-reference with character profiles and other deep dives to build the full picture.
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