Where: the Oldest House, then the Unknown, the zone of floating islands reached from the Oldest House roof, and a retro flashback.
Main missions: the ninth to eleventh of Contain the Crisis.
Watch for: a new enemy type, the Hedron, which shrugs off raw damage: use secondary attacks and Fire or Mold damage. Three Hedron bosses: the Hedron Parallel, then the Hedron Factor and Hedron Proxy in either order. Pope's Research is listed as a side story but you cannot cross the Unknown without it. Trophies: The First Link and Stop it at the Source (both bronze). Each mission gives 1 Living Shard. Once The Hedron Link is done, Zoe calls for Zoe's Briefing at the Watchtower, which opens New Growth and Maintenance Protocol; see the side quests page.
1. The Hedron Link
Starts in the Oldest House straight after The House in Distress. Rewards: 1 Living Shard and The First Link (bronze).
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1
Rescue Pope
Go back through Prime Candidate Testing. In the chamber with the smashed cell you meet Hedron enemies for the first time; basic attacks barely hurt them, so lean on secondary attacks and Fire or Mold damage. Fight through the next rooms, then use the intercom beside the Main Test Chamber door to reach Pope. She opens the door; talk to her inside.
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2
Up the Main Test Chamber
Climb the stairs into the Main Test Chamber and use Shift on the wall to follow the moving pillar up; the left and right routes meet. Do not walk back down the mirrored wall, which only leads to dead ends: the way on is near the end of the moving pillar, through the prison cell gates. Keep climbing the tower across the outdoor gaps, fighting as you go. In the hallway where gravity keeps changing, follow the red carpet. At the Unknown location, use the Patterned TV.
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3
Boss: Hedron Parallel
Kill the smaller enemies around it and stay out of its projectiles. The main body only takes damage once a good part of its health has gone through those enemies. As with every Hedron, secondary attacks and Fire or Mold damage do more than raw hits. Afterwards turn round, take the elevator nearby back to the Oldest House and talk to Pope to finish the mission.
2. Sever the Hedron Links
Starts in the Oldest House. Two links to sever, each guarded by a boss, in either order. Rewards: 1 Living Shard and Stop it at the Source (bronze).
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1
Back to the Unknown
Take the elevator above Pope to Roof Access; it brings you out where you first entered the Unknown.
- Fast travel door: Oldest House Rooftop. At the entry point.
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2
Pope's Research: the Gravity Wells
The islands are linked by Gravity Wells, and they only appear as you work through Pope's Research. On each island, jump onto the weather balloon, cut it down, break the crate it was carrying and set the probe relays inside on the red circles. The minimap shows a signal icon and the antennas beep near the right spot; a green light means it is placed right, and a Gravity Well opens to the next island. There are eight balloons; most hold two relays, one holds three and one holds four.
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3
Link near the Patterned Evac Building: Hedron Factor
On the south island, on the way to the Evac Building, find the platforms out to the island with the link, jump across and use the TV. The Hedron Factor sends heavy enemies in one after another: kill two in a row, and when the health bar reaches its blue marker, smaller enemies come in among dropped mines. Stay off the mines while you clear the small ones, then go back to the heavies. Repeat until it falls.
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4
Link near the Patterned Field Office: Hedron Proxy
On the north-east island, on the way to the Oldest House, climb the platforms to the island with the link, jump across and use the TV. The Hedron Proxy is built from heavy brick enemies that charge: dodge the charge and hit the one that charged. In the last phases small enemies come in on the ground alongside the heavies, so keep track of both. With both bosses down, the mission ends.
3. The Unknown's collectibles
Nine collectibles and eight fast travel doors. Several need Pope's Research finished first, because that is what lets you reach the islands. In the order of the zone's collectible list:
- FBC Taskboard. Near the Oldest House fast travel point, once the Central Zone Taskboard is unlocked.
- Secret Hideout. Inside the Pulse Fitness shop, the one with the purple sign. After Pope's Research.
- Dylan's Sketchbook: Art Exhibition. A gallery puzzle. After Pope's Research, and it needs Shift.
- Testing Facility. Through a pipe in a construction pit west of the Twisted Rooftops fast travel door.
- Freeze Frame camera #1. At the construction site, behind the blue Mold hole; reachable any time.
- Dog. On the north-west island, after Pope's Research.
- Freeze Frame camera #2. In the shop with the garage puzzle.
- Dylan's Sketchbook: Game Night. A board game puzzle on the south-east island. After Pope's Research.
- Taxi. On the north side of the Evac Building island.
Also opened by Pope's Research: the Unknown Resonant, the Co-Director, on the Resonants page, and A New Directive, which calls you on the north-west or south-west island.
4. Rebuild
Starts right after Sever the Hedron Links. A retro flashback with Jesse at Dylan's side; her area attacks followed by Dylan's normal attacks handle the fights. It runs in a straight line. Reward: 1 Living Shard.
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1
The letters, the house and the General Store
On the black and white screen, collect the letters of DYLAN: Y top right, L top left, A bottom right, N bottom left, then go back to the centre. Pick up the backpack at the bottom of the screen, go downstairs and leave by the left side of the kitchen. Head north through town, beat the bullies with Jesse, and in the General Store pick up a Donut, Potato Chips and a Soda, then talk to the cashier.
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2
The Dump: five projector slides
Go north-east through the tunnels to the Dump, fighting on the way. Two slides are on the left path, one on the top path by the water, and two on the right; the upper one on the right needs the rat enemy dead. Take them to the projector.
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3
Through the projector
Each time you use the projector the scene changes. First: go through the doorway it reveals, use the window inside, walk through the wall under the shadow where the footsteps lead, inspect the group of dolls at the top and leave. Second: explore the new area and leave by the shed. Third: cross the dark area north and walk through the wall at the top left; you leave on your own at the end. Last: follow the path up and leave the slide. Then go home, by fast travel or on foot, and up to the bedroom.
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4
The Oldest House, the cave and the Dump again
In the Oldest House, talk to Dr. Darling, collect the five slides in the same order (left pair, top, right pair), use the central projector, pick up the flashing spot on the right and leave. In town, go right past Sled Hill to the cave, kill the monster at the slide door and the two after it. Go home and use the game console in the bedroom; in the changed scene, find Dr. Darling left of the projector and use the sparkle. Back in the cave, get round the enemies to the projector at the top, then return to the Dump and fight; Jesse runs off.
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5
The shards and the last room
Talk to Dr. Darling in the centre of the Dump and take the third shard, then use the projector at the top of the Dump. Go south to the school, talk to Dr. Darling and lead the way back to the Dump projector. Head north through the hallway, try the elevator, take the last shard, use the central slide, go up and talk to Jesse, then use the projector and go into the room. The scene after it returns you to the normal world.
5. Part 5 Completion
✅ Before Heading for the Core...
Cross-checked
Cross-checked on 2 October 2026 against the guides of PowerPyx and KeenGamer and GameRant's mission list. The steps, the three Hedron fights, the balloon count and the Unknown's collectibles are PowerPyx's; KeenGamer and GameRant agree on the order of the three missions. Not from a playthrough: nobody here has played it, and what the sources do not describe is not on this page.