The Synthesizer is a wound that learns to sing; it hummed under my hands as the terminal blinked red. I shoved the Sparkleaf sample into the tray, and the map’s alarms answered like a distant drumbeat. You have ninety seconds between injection and either extraction or a very expensive respawn.
I’ve run Parasitism 5 several times for Sekiguchi, and I’ll walk you through the smallest mistakes that turn a quick contract into a nightmare. Read this once, then use the map and the Synthesizer with purpose.
The Bio-Research and Quarantine POIs sit in opposite corners of Marathon’s map.
That distance matters because Parasitism 5 is three tight steps: grab a Sparkleaf sample, synthesize a SIMbiont in Quarantine, inject it, then survive long enough to exfil. Miss one beat and you’ll be back at base with nothing to show for the risk.
- Extract biotic sample from Sparkleaf in Bio-Research
- Synthesize SIMbiont in Quarantine and inject yourself
- Allow the SIMbiont to integrate with your shell; then exfil
The Bio-Research greenhouse pockets are full of vegetation that hides the Sparkleaf.
Go north on the map and sweep the vegetation. Sparkleaf isn’t pinned to a single rock—it’s common, but easy to miss if you sprint past the undergrowth.
Where can I find Sparkleaf in Bio-Research?
You’ll spot Sparkleaf among the low foliage. I usually circle the northern greenhouse and keep an eye on quest markers: they’ll point you to the extraction terminal once you have the plant.
Once you’ve got the plant, head to the numbered terminal shown below. Put the Sparkleaf in the extractor’s inventory and wait a few seconds for the biotic sample to process. Don’t hang around—collect the sample and move.
Quarantine sits in the southwest and carries a heavier guard presence than Bio-Research.
Move fast but don’t run blind. I take a stealthier route to avoid UESC patrols and reach the small room where the Synthesizer waits; the quest marker will light up when you’re in range.
How do I synthesize SIMbiont in Quarantine?
Place the biotic sample into the Synthesizer’s slot and start the program. The terminal will craft a SIMbiont item you can pick up. Inject immediately or plan your cover—once consumed, the timer starts and so does the UESC response.
How long do I need to survive after injection?
The SIMbiont requires 1 minute and 30 seconds to integrate. That’s 90 seconds of concentrated pressure where the UESC will hammer your position. Treat those seconds like a sprint-run hybrid: controlled aggression to thin the enemy, then a quick exfil out of the POI.
Practical survival tips: pick cover with multiple exit routes, bring suppression tools or a frag to force space, and don’t try to solo rush a chokepoint. I prefer to bait enemies into a funnel then drag them back to a corridor where the map becomes a live wire under your feet.
When the timer ends, extract from the map to complete Parasitism 5 for Sekiguchi and claim your reward. You’ll earn faction progress and a reputation that matters when later contracts ask for higher-risk plays; Bungie balanced Marathon so those moments reward players who move with intent.
Ready to inject and trust a parasitic program to rewrite your loadout—will you test the SIMbiont or walk away with your shell intact?