How to complete the Marathon Parasitism contract for Sekiguchi

The Marathon Parasitism quest for Sekiguchi is especially tough and long, requiring you to venture across Outpost and Dire Marsh several times. As part of Nona's experiments, you've got to do all sorts of field testing and research in your Marathon runs, including things like stealing data drives in the highly secure Pinwheel Base, collecting all sorts of salvage, and synthesizing numerous samples and then injecting them into yourself for good measure – as if Runner life wasn't hard enough! Since this can be a rather laborious priority contract chain, I've laid out every step of Parasitism below to help you complete it as efficiently as possible.

How to get Combat Data and a UESC Data Bank for the Marathon Parasitism contract

Once you've completed the Marathon Introducing Sekiguchi and the nice and easy Baseline Calibration contracts, you can begin the first priority contract in a five-part chain called Parasitism.

For the first step of Parasitism, you need to head to Outpost and pick up combat data from defeated UESC Ghosts on a rooftop in Processing, collect a Data Bank from the middle of Pinwheel Base, then deliver that Data Bank to a Marathon DCON. All that needs to be completed in a single run too.

This contract really throws you in at the deep end, and if you don’t know how to get into Pinwheel Base in Marathon, I highly recommend reading the linked guide and even spending a run or two playing as Rook to learn the layout and entrances – I once got so lost in the base that I failed to exfil in time.

Here's what you need to do to complete step one of Parasitism:

1. Head to Processing in the southwest section of Outpost and get onto the rooftop of the western building. There are all sorts of ladders, stairwells, and climbable objects you can use to get onto the roof, so it isn't difficult to reach so long as you keep going up.
2. Kill the two Ghosts on the rooftop marked on the above map and collect the UESC Combat Data cards they drop.

3. Get inside Pinwheel Base. Again, used the linked guide above to learn how to get into the base or see if other players have opened the way for you.
4. Head towards the center of Pinwheel Base, sticking to the ground floor. You'll eventually reach a white and blue atrium with your objective inside.
5. Eject and collect the data bank, then leave Pinwheel Base.
6. Get to a DCON device and drop off the data bank. There are DCONs in Airfield, Orientation, and Processing, so go to whichever is closest from where you exited Pinwheel Base.

7. Get to a DCON device and drop off the data bank. There are DCONs in Airfield, Orientation, and Processing, so go to whichever is closest from where you exited Pinwheel Base.

For your efforts, you'll get a bunch of Cores, 1,500 Credits, some Unstable Diodes, and some Codex intel from Nona., and she'll also set you up with part two of Parasitism.

Marathon Parasitism Fractal Circuit and Storage Drive locations

For the second priority contract in the Parasitism chain, Nona tasks you with collecting and exfiltrating 12 Fractal Circuits, Paradox Circuits, or Neural Insulation and 12 Storage Drives, Amygdala Drives, or Predictive Frameworks. You can do this on any of the Marathon maps and across any multiple runs as every time you exfil, progress is permanently banked.

Any combination of items is acceptable for each objective too, and the higher a salvage item's rarity, the greater the progress it grants. For example, Amygdala Drives and Paradox Circuits are worth four each, so collecting two Amygdala Drives and four Storage Drives would count as 12 for the objective.

Here's where to look for all these salvage items:

• Fractal Circuits (Enhanced):
  • Perimeter: North Relay
  • Outpost: Flight Control, Dormitories, Pinwheel Base
  • Any map: Core Storage and Locked Rooms (Deluxe rarity or higher)
• Paradox Circuits (Deluxe):
  • Perimeter: North Relay
  • Outpost: Flight Control, Dormitories, Pinwheel Base
  • Any map: Core Storage and Locked Rooms (Deluxe rarity or higher)
• Neural Insulation (Superior):
  • Perimeter: North Relay, Hauler
  • Dire Marsh: Algae Ponds
  • Outpost: Flight Control, Dormitories
  • Any map: Locked Rooms (Superior rarity or higher), Lockdown Zones (these seem to appear on Dire Marsh only for now)
• Storage Drives (Enhanced):
  • Perimeter: South Relay
  • Any map: Core Storage
• Amygdala Drives (Deluxe):
  • Perimeter: South Relay
  • Any map: Core Storage and Locked Rooms (Deluxe rarity or higher) on any map
• Predictive Frameworks (Superior):
  • Perimeter: Station, South Relay
  • Outpost: Flight Control, Dormitories, Pinwheel Base
  • Any map: Locked Rooms (Superior rarity or higher), Lockdown Zones (these seem to appear on Dire Marsh only for now)

Overall, Outpost is going to be the best map for getting this contract completed quickly due to its increased loot quality, but that's assuming you also exfil successfully too. Otherwise, Perimeter is your best bet. I've also found that defeated UESC enemies of any kind can also drop some of these items, so it's worth looting them to see if they turn up anything handy.

Once you've got everything, cash the contract in with Nona to get even more Cores and Credits and move onto Parasitism 3. At this point, you might have enough salvage and other resources to start unlocking some upgrades from Sekiguchi and other Marathon factions.

Marathon Parasitism Sparkleaf locations and how to extract and inject the Biotic Sample

Now Nona wants you synthesize a Biotic Sample in Dire Marsh and test it on your shell to see its effects. So, you need to start a run on Dire Marsh and collect a Sparkleaf, take it to a machine in Bio-Research to extract the Biotic Sample, then inject the sample in Quarantine and exfil safely. It's quite a big ask as not only do you need to do all of this in one run, you have to get out too, so here are some pointers on what to do:

1. Find one Sparkleaf. The best place to look is Greenhouse but you can also find it growing in the grassy areas of the map, such as the marsh area surrounding the Anomaly.
2. Go to Bio-Research and get to the upper floor of the western building. You should be directed towards a large, orange extraction machine.

3. Interact with the extraction machine and put the Sparkleaf inside, exactly like a DCON.
4. Collect the Biotic Sample it spits out.
5. Head all the way over to Quarantine and get to the large central area.
6. Locate the small lab under the yellow scaffolding and place the Biotic Sample inside the material synthesizer machine. Again, this works just like a DCON and the previous machine you used.

7. Pick up the Injectable Biotic Syringe the synthesizer spits out. Your Runner will automatically inject it and this doesn’t seem to cause any ill effects.
8. Exfiltrate safely.

Nona will reward you with a backpack, more Cores and Credits, and some other bits, and you'll be able to move onto part four of Parasitism.

How to download research clearance in Maintenance and extract a Synthsilk Sample in Marathon

Nearing the end of Parasitism, Nona now needs your shell's synthsilk data, which means another trip to Dire Marsh. Firstly, you need to download research clearance in Maintenance, then extract a Synthsilk Sample in Bio-Research, and finish by sending your sample off in a DCON – sounds simple but you need to do it all in one run and it's quite the trek across the entire marsh, so come prepared:

1. Go to Maintenance and climb up to the upper walkways of the main warehouse building.
2. Head south and go inside the control room. If you're playing with a crew, make sure they join you in this room.

3. Interact with the orange terminal roughly in the middle of the room to download clearance. This also seals the room and triggers some UESC robots to attack, including a Ghost Commander. Once all the robots are dead, you can leave.
4. Go across the map to Bio-Research and get up to the upper level of the west building.
5. Explore the southeastern side of this upper level to find an orange machine mounted between a window and a whiteboard.

3. Interact with this machine then collect the Synthsilk Sample.
4. Head over to any DCON in Dire Marsh and place the Synthsilk Sample inside. The Greenhouse DCON is closest.

Exfil, cash in the contract, and Nona will reward you with an assortment of Deluxe and Enhanced Cores and more. Then it’s time to wrap up the Parasitism priority contract chain.

How to synthesize and inject the SIMbiont for the Marathon Parasitism contract

For the fifth and final Parasitism priority contract in Marathon, Nona wants you to synthesize and implant her prototype SIMbiont. This contract is pretty much a repeat of part three of Parasitism too, including the fact that everything needs to be achieved in one Dire Marsh run with a successful exfil. Here's a quick rundown of all the necessary steps:

1. Find one Sparkleaf and place it inside the orange extraction machine in Bio-Research. This is exactly the same process as in Parasitism 3/5.
2. Collect the Biotic Sample and then leg it to the central area of the main Quarantine building.
3. Go into the blue and white laboratory on the western side of this area and place the Biotic Sample into the orange synthesizer machine.

1. Collect the SIMbiont 0.1 – when you do this, you'll be locked in the lab – then kill the attacking UESC forces. The red barriers will drop and you'll be able to leave once they're all dead.
2. Exfiltrate safely.

Hand in the final Parasitism priority contract to Nona and she'll give you several Deluxe Runner Cores as well as eligibility for Sekiguchi's Priority Access wares in the faction's Armory tab. However, you now need to increase your Sekiguchi rank to level 10 if you want more priority contracts to complete, and the best way to rank up is to complete any standard contracts they offer.

Marathon tips: Help for beginner Runners
Marathon classes: Who you can play as
Marathon Introducing NuCaloric: Get an ID
Marathon Introducing Traxus: Bestie Vulcan
Marathon Tox Clear: Vent gas, grab loot
Marathon error codes: Issues and fixes

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