Brittle Hollow is the third of six planets in the Outer Wilds' solar system. Its surface is largely barren and rocky, and over time it will break apart and fall into a black hole at the center of the planet. Brittle Hollow is home to an enormous Hanging City, the Tower of Quantum Knowledge, the Southern Observatory, a Gravity Cannon, and the Black Hole Forge used by the Nomai to craft the warp cores for the Ash Twin Project.
Details
Features
Brittle Hollow is a highly unstable planet that formed naturally around the black hole at its center. Its dry, rocky surface is fractured and prone to collapse, and in the 22 minutes of game time the player can observe as most of the planet's crust breaks away and falls into the black hole. These pieces then emerge at the White Hole next to White Hole Station. This collapse is precipitated by the balls of lava ejected from the planet's moon crashing into the surface. Traversing the planet's precarious remains is a challenging task, but despite the likelihood that a player will slip and fall into the black hole, the fact that White Hole Station lies very close to the black hole's exit point means that the planet's long drops aren't as dangerous as they are simply inconvenient.
Escape Pod 1 resides on the surface, its metal tempered by the heat of its descent to the planet. From the escape pod the player can follow a trail of precarious wooden bridges created to span the gaps between rocks, indicating that the enormous drop towards the planet's core existed millennia ago when the Nomai first entered the system.
The planet's two poles are topped with snow, and the north pole has flowing water. This leads to ice formations beneath the surface into which the Hanging City is built.
The rest of the planet's interior is made up of a mixture of blue metallic and red crystalline rock formations. The geometric lattice of these formations exhibit clear fracture points and planes of weakness, which makes it susceptible to the collapse that the player can witness in action during the game.
Locations
Northern Glacier
The icy northern pole of the planet, which possesses several ruined Nomai structures lying above the Hanging City. The Nomai warp receiver connected to the White Hole Station's warp tower is present here, and nearby Nomai writings discuss the negative time discrepancy between warps.
A larger ruined building possesses two gravity lifts connected to the Hanging City, however, the lift down into the city is blocked and non-unfunctional. However, a secret cavern hole into the City lies in a nearby frozen river.
Hanging City
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The Hanging City is the biggest Nomai settlement in the Solar system, hanging to the ice under the Northern Glacier where the planet's crust was stable enough for a long-term settlement. Having moved from the Old Settlement, the Nomai in Brittle Hollow both survived and thrived. The City is divided into four districts located on top of each other, all accessible by a tall vertical passageway with gravity panels.
From highest to lowest, the districts are the Black Hole Forge District, the Eye Shrine District, the Meltwater District, and the School District. The vertical passageway is broken near the top, cutting off conventional access to the Black Hole Forge District.
Black Hole Forge
The Black Hole Forge is a massive Nomai structure, suspended on rails attached next to the Hanging City. The Forge itself can be moved along these rails from a control room in the Meltwater District, and can be raised up to the highest level of the Hanging City, or lowered down to the black hole at the planet's core, where it is by default.
The Forge can only be accessed when raised to the uppermost level of the Hanging City, which is constructed entirely out of gravity panels attached to the underside of the planet's crust, therefore being upside-down. The district contains a warp receiver, connected to Brittle Hollow's corresponding warp tower on Ash Twin.
The Nomai used the Forge to craft the warp cores used throughout the solar system from the black hole itself, as well as the Advanced Warp Core for powering the Ash Twin Project.
Meltwater District
The second lowest level of the Hanging City. It is connected to the Crossroads by two bridges, and houses a control room that raises and lowers the Black Hole Forge. Ruined Nomai buildings contain writings detailing methods of procuring an advanced Warp Core for the Ash Twin Project, as well as a hole that leads to the surface.
Eye Shrine District
The Eye Shrine District, similar to the identically named district in Ember Twin's Sunless City, houses many derelict Nomai buildings and a small shrine with writing detailing the Nomai's thoughts and knowledge about the Eye of the Universe.
School District
The lowest district, made for the children who lived on Brittle Hollow. Inside are classrooms with writing explaining the Nomai's history stuck in the solar system and the Nomai tradition of 'festivals'. From here, a long gravity crystal path runs along the underside of Brittle Hollow's crust that leads to the Old Settlement on the planet's equator.
Crossroads
A two-leveled central hub location under Brittle Hollow's surface, that contains Riebeck's camp, a map of the Nomai structures on the planet, and acts as a central node between most of them. The map depicts the important Nomai locations and pathways that exist between them, though centuries of deterioration means some of the pathways have broken down and will continue to do so over the course of the loop.
The Crossroads can be accessed from a small Nomai settlement on the planet's equator surface, the Gravity Crystal Workshop, where Riebeck's first camp can be found, as well as directions to their current camp. The settlement and both levels are connected by gravity crystal paths, with the bottom level also possessing a gravity lift leading up from the black hole, intended to potentially save any who accidentally fall towards the black hole by returning them to the Crossroads.
As depicted in the map mural, the Crossroads connects to the Hanging City by two large bridges, and the Gravity Cannon and Tower of Quantum Knowledge by a system of gravity lifts. However, the deterioration of Brittle Hollow's crust heavily affects these pathways over the course of the loop.
Gravity Cannon
A massive Nomai structure on Brittle Hollow's equator, intended to launch Nomai shuttles with gravitational force, accessible from the Crossroads or the surface. The cannon is linked to a shuttle belonging to a Nomai named Solanum, now currently on the Quantum Moon. The shuttle can be recalled using the cannon's controls to read the notes inside written by Solanum, just after landing the shuttle on the Quantum Moon and just before setting foot outside.
From the Gravity Cannon, the Southern Observatory can be reached via a series of gravity lifts and broken platforms of crust. However, the gravity lifts are misaligned due to the planet's deterioration, and care must be taken when transferring between lifts using the jetpack. Note that the Gravity Cannon is likely to fall through the black hole near the end of the loop.
Hollow's Lantern
Brittle Hollow is orbited by the volcanic moon, Hollow's Lantern. The lava level slowly lowers as time goes on. The balls of magma that shoot from the moon crash into the surface of the planet, precipitating the collapse of the planet's crust. The Nomai named Root used the moon's lava to heat-test mineral samples supplied from the Nomai mines on Timber Hearth. These samples were then used to encase the Ash Twin Project.
Old Settlement
The original Nomai settlement, located on the equator under the crashed Escape Pod 1, where the Nomai inhabiting the pod first made their home on Brittle Hollow, hidden under the surface to shelter from Hollow's Lantern. A pathway of fragile stone stairways and bridges leads to the settlement from the Escape Pod, and also connect the ruined houses and pathways within, collapsing under enough force.
Nomai murals and writings can be found throughout detailing the Nomai's history regardingthe Escape Pod's jettisoning from the Vessel, revealing the Vessel's ensnarement in Dark Bramble and the other Pod locations. After a while, the Nomai realized this part of the crust was still too exposed to Hollow's Lantern's bombardment, and they moved north along a gravity crystal path underneath the crust to settle in a safer place, eventually creating the Hanging City.
Southern Observatory
A domed Nomai observatory on the south pole. The entrance on the surface is broken from the outside, with the only accessible route being beneath the surface. Riebeck's ship and recorded notes of their plan to search the Nomai ruins on the equator for a path underground lie outside the surface entrance.
The Observatory can be accessed from underground via the broken gravity pathways from the Gravity Cannon, requiring care to traverse and move from pathway to pathway without falling.
Within the Observatory is an Eye Signal Locator, built after and more sophisticated than the Locator on the Attlerock. The Locator's modules can be individually activated to show the orbits of each planet in the solar system, including the Eye of the Universe. However, the Locator is also unable to locate the Eye's orbit, erratically creating models of potential orbits instead.
On the same level as the Locator controls are two conversations about the Nomai's ongoing search for the Eye. One covers what they know about the Eye so far and laments their lack of progress finding it. In the other, the Nomai Mallow suggests simply launching a probe into the outermost reaches of the solar system to see if it happens to find the eye. Cassava points out that the odds of randomly firing the probe at the correct trajectory to find the Eye were extremely small, but Conoy points out there's another ongoing project that could take luck out of the equation.
Also contained in the Observatory are two active models of Giant's Deep cyclones, created by a Nomai named Spire to aid the team building the Orbital Probe Cannon. The models depict two varieties of cyclone - the most common spinning clockwise and upwards, and a rare variety that spins anticlockwise, and forces things downwards instead. Next to the entrance is a projection stone of a conversation with the team building the orbital probe cannon on Giant's Deep, who had been using the cyclones to launch parts into orbit only to have one piece unexpectedly driven beneath the ocean's usually-impassable current.
Tower of Quantum Knowledge
A massive Nomai tower, suspended from a section of Brittle Hollow's crust where the Nomai found a Quantum Shard, the Tower Shard, and contains information crucial to the Quantum Moon pilgrimage. While the tower's bottom level can be easily reached via the Crossroads or the surface, the upper levels are inaccessible by conventional means at the start of each loop, as the gravity panel path leading into the tower is broken and impassable.
However, the planet's ongoing destruction is likely to drop the tower through the black hole partway through the loop, and, once it exits at the White Hole Station, can be freely explored in zero-gravity.
The surface of the Tower contains the Tower Shard and other quantum objects affected by the Shard. The Shard itself has a Nomai writing wall attached to it that also transports with it, providing a mild hint to the rule of quantum entanglement.
The upper levels of the tower contain two scrolls (one congratulating a Nomai named Solanum on reaching the last step before she travels to the Quantum Moon, and one on a shelf that reminds the pilgrim that they're they're taking part in a tradition of curiosity and exploration by following in the footsteps of everyone before them who sought the Quantum Moon) and a Quantum Moon Locator.
Texts and recordings
Crossroads | |
Riebeck’s notes outside crossroads
The journey here from the south pole has been, um... I’m going to go with “harrowing”, because of the, um, all of the meteors. But hey, at least I made it here unconcussed and not on fire! Okay, let’s see... I poked around a little, and there’s some sort of old Nomai path that starts across from my campsite, inside the ruined building with trees growing out of it. Doesn’t look like anything horrible - just stairs leading down. I can handle stairs! After I get my supplies together, I’ll follow the path and see where it leads. |
Riebeck’s journal Hurgh. Well. That was... deeply unpleasant. I made it this far, though. Guess that’s the part to focus on, and not how I’ll eventually have to get back up that path. But wow, this place sure is something! Looks like the Hanging City is north from here. And east is a gravity cannon! I definitely want to see that And another thing - I’m detecting oxygen from somewhere below. Which is good, since I, uh, used up a lot of my supply screaming during the trip down from the surface. As soon as I stop dry heaving, I’m going to head farther down below so I can refill my tank. |
Escape Pod 1 | |
Escape Pod Flightlog
BEGIN FLIGHTLOG: Escape Pod 1. Vessel has been mortally injured. Emergency sequence activated. Awaiting departure from Vessel. Launching Escape Pod 3... Launching Escape Pod 2... Now launching Escape Pod 1. ALERT. Collision imminent. Preparing for impact. Scanning external environment... Scan complete. Minor structural instabilities detected. Pockets of breathable air detected. Adequate solar energy detected. Verdict: HOSPITABLE. |
Outside pod recording THATCH: Is everyone unharmed? PLUME: No one was badly injured from the escape pod’s impact. We’re incredibly fortunate. THATCH: This is good news, at least. Have we heard from Escape Pod 2 or Escape Pod 3? FILIX: No, I... I’m unable to make contact. My equipment can hear the other two escape pods’ distress signals, however. If it’s any comfort, both pods must be structurally intact. FILIX: I’ll continue calling for them. THATCH: My gratitude. If we can — PLUME: Thatch, the moon is approaching again! THATCH: Everyone brace yourselves, swiftly! The volcanic moon has returned! THATCH: Be cautious of falling ash and debris! PLUME: ...I believe the moon has passed. FILIX: This planet doesn’t appear eager to have guests. We are certainly unwelcome on its surface. THATCH: We need to find shelter, and quickly. The volcanic moon won’t be gone for long. PLUME: I observed several promising sites below the surface, but we’ll need to construct a way for everyone to climb safely down this cliff. Perhaps we could build platforms? |
Gravity Cannon | |
Information text
The shuttle is currently resting at the Quantum Moon. Call the shuttle home Activate the gravity cannon |
Solanum's pilgrimage SOLANUM: I’m at the shuttle! I’m ready to make my first pilgrimage to the Quantum Moon. BELLS: That’s exciting! You’re almost ready, but there’s still one more rule you need to learn. Come see me at the Tower of Quantum Knowledge. BELLS: The tower is on the opposite side of Brittle Hollow. If you follow the path west to the Crossroads, you can reach the tower from there. SOLANUM: My gratitude for the directions, Bells. I’ll see you soon! |
Solanum's Shuttle recording SOLANUM: I am here! After watching it wander the skies for so long, I am about to stand (for the first time) on the Quantum Moon. SOLANUM: As expected, my shuttle has landed at the moon’s south pole. I will make the remainder of my journey on foot. SOLANUM: We don’t know why the Quantum Moon always welcomes its visitors at the south pole, just that this is true. SOLANUM: As a child, I considered such unknowns sinister. Now, though, I understand they bear no ill will. The universe is, and we are. SOLANUM: I am ready. |
Hanging City - Black Hole Forge | |
Advanced warp core
CLARY: I have good news, Yarrow! The advanced warp core is ready to be installed in the central chamber of Ash Twin.
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Aligning towers CLARY: Regarding the warp towers on Ash Twin: Does each tower have to be perfectly aligned with the center of the astral body to which it’s tuned?
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Boarding area WARNING: Be cautious near the boarding area while the Black Hole Forge is in operation. |
Core delivery ROOT: Where am I taking this first black hole core? (And where am I taking the remaining cores once they’re ready?)
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Warp Tower designs POKE: Of note: Yarrow believes he spotted a flaw in the warp tower designs: namely, that one of the warp towers on Ash Twin will never activate, because its warp receiver will never align overhead.
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Warp platform (dependent on in-game time, arrival time is always one hundred-thousandth of a second earlier than departure time) Departure Time: XXX.XXXX Arrival Time: XXX.XXXX Return warp status: CHARGED. Step onto warp platform when ready. |
Hanging City - Meltwater District | |
Advanced Warp Core search
The Ash Twin Project requires a powerful, highly advanced warp core. How should we obtain it? |
Warp Core solution 1 Solution 1: We could retrieve the warp core from the Vessel.
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Warp Core solution 2 Solution 2: We could craft a new advanced warp core inspired by the Vessel’s warp core.
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Poke's thoughts on warp core creation POKE: I feel strange, trying to recreate Annona’s warp core without him. At times, it still feels strange to no longer be his (very young) apprentice, and for the Black Hole Forge to be in my care and not his.
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Hanging City - Eye Shrine District | |
Cassava recording
CASSAVA: I imagine I’ve been hard on Poke, again. This in turn means I’ve made things difficult for her sister (Clary). CASSAVA: If Poke and I are oil and water, Clary is our emulsifier. She certainly makes us a better team than would mixing through shaking (although sometimes I would like to shake Poke!). CASSAVA: Jokes aside, suppose my own fear of never finding the Eye prompted my argument with Poke. That would be immature of me. CASSAVA: I should apologize... At least to Clary, who could then tell Poke. |
Eye Shrine welcome Be welcomed in this place. This shrine is a space to reflect on what brought us to this star system: the signal from the Eye.
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What is the signal What is the Eye’s signal?
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Eye age How can the Eye be older than the universe itself?
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Solanum and the Eye SOLANUM: I no longer believe, as I did as a child on Ember Twin, that the Eye of the universe (the source of the signal) wishes to harm us. But it may not want to be found, either.
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Hanging City - School District | |
Festivals
LAMI: Explanation of Festivals
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Ilex new Vessel arguments
ILEX: Why We Should Build A New Vessel
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Solanum school text SOLANUM: Formation Of This Universe
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Northern Glacier | |
Feldspar's notes
FELDSPAR’S SPARE JETPACK FUEL It’s annoying to schlep across the planet to the ship if I can’t use my jetpack, so I’m leaving this here. I checked with my Little Scout — I do>too use it, Hornfels, ya burnt marshmallow — and the scout’s integrity reading said this piece of Brittle Hollow is as stable as any, but who knows. If the fuel’s still around, feel free to use it. If not, well, wherever you’re reading this note, I’m sure you’ve got bigger problems. |
Quantum Moon observations FILIX: Has anyone observed the phantom moon that sometimes greets us in the night sky? Your thoughts interest me.
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Recreation of warp travel CLARY: To our friends on Brittle Hollow: I just warped here from the White Hole Station (on the other side of Brittle Hollow’s black hole)! Our design worked; we’ve successfully recreated warp travel!
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Warp platform (dependent on in-game time, arrival time is always one hundred-thousandth of a second earlier than departure time) Departure Time: XXX.XXXX Arrival Time: XXX.XXXX Return warp status: CHARGED. Step onto warp platform when ready. |
White Hole Station arrival and departure times PYE: Ramie and I reviewed the records you sent, Poke, and they appear to show Nomai are arriving at the warp receiver on Brittle Hollow slightly before departing from the White Hole Station.
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Old Settlement | |
Entrance text
PLUME: Of note: Be sure not to wander far from here. Though this area is somewhat unstable, it’s safer than any we’ve found so far.
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Eye signal knowledge THATCH: This knowledge is too dear to lose: Here is everything we can recall about the signal we encountered while aboard the Vessel.
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Vessel crash recording
THATCH: I can’t understand. Why did the Vessel crash in that place? PLUME: Was the Vessel unwell in some way? FILIX: No, Annona and I checked before the warp, and the warp core and navigation systems were both well. FILIX: We warped to follow that curious signal from the Eye of the universe. Where we arrived was wrong; it wasn’t where we tried to go. THATCH: Suppose it wasn’t a problem with the Vessel, but with our destination. FILIX: I’m afraid for our friends in Escape Pod 3.... |
Plume's brother PLUME: My brother wasn’t in Escape Pod 1 with us. Was he in Pod 2, or Pod 3? Was he able to board an escape pod at all?
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Keek PLUME: The pain of your absence is sharp and haunting, and I would give anything not to know it; anything but never knowing you at all (which would be worse).
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Foli missing KOUSA: We can hear the other escape pods’ distress signals, which gives me hope. Foli, are you still here? I am unsure how to survive in this place without you.
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Thatch and loss
THATCH: Is the hardest part of this tragedy not knowing who we may have lost? Or will the hardest part come later, when we learn? (Be well, Aunt Melorae...) |
Ilex poem ILEX: Look out, look out below!
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Black Hole warning PLUME: Use caution! A black hole sleeps below. You must not slip. |
New settlement discussion PLUME: Given concerns about our settlement’s stability, where should we construct a new, less temporary shelter?
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Southern Observatory | |
Giant's Deep's current
CASSAVA: Conoy, Daz and I were lifting Orbital Probe Cannon components into orbit for assembly, and one somehow sank down down(sic) beneath the current.
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Giant's Deep's cyclones CONOY: Cassava’s Construction Yard has been using the cyclones on Giant’s Deep to lift Orbital Probe Cannon parts into orbit, but one component was pushed down past the current that usually prevents anything from sinking.
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Knowledge of the Eye
CONOY: What have we learned thus far in our search for the Eye of the universe?
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New methods to search for the Eye CONOY: How should our methods change as we continue our search for the Eye of the universe?
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Riebeck's recording outside observatory I’m here! I did it! I put the ship down safely! Um, in that the ship went down, and I didn’t sustain bodily harm. A few minor repairs, and it’s like the ship never even hit those rocks! One of my better attempts. Feldspar would barely have laughed at me, I bet. That’s the good news. The bad news... I, uh, haven’t found a way inside this structure yet. The door is broken, and I know I’m not great at exploring, but I think I would have found a different entrance by now if there were one. P... probably. I can’t get inside from here, but I know there are paths below the surface. I’m going to head north to the ruins on the equator to try to find a way down. |
Tower of Quantum Knowledge | |
Grove observations
PLUME: The trees are moving! The trees in this grove wander about freely (the entire plant, roots and all)! This is not normal, even for this alien planet. And I never see them move! Is that even possible?!
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Tower description from surface BELLS: Beneath your feet lies the Tower of Quantum Knowledge.
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Tower Shard THATCH: Plume, Filix, and I have determined this atypical shard of rock is the reason objects in this grove are behaving in a quantum manner.
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Bottom of the tower BELLS: Be welcomed in this place! Above you stands the Tower of Quantum Knowledge.
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Pilgrimage information BELLS: If you’re here to make your first pilgrimage to the Quantum Moon, you are almost prepared to set out on this deeply significant journey. Before you do, pause, and remember your history.
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Solanum's mentor
BELLS: Welcome, Solanum! Your arrival here means you’ve completed your preparations on Giant’s Deep and are ready to depart for the Quantum Moon.
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Gallery
Notes & Trivia
- If you happen to slip and fall towards the black hole, its possible to slingshot yourself around it using your spacesuit's thrusters. There is a conveniently placed gravity lift extending down to black hole's edge, and lucky or skillful players that can maneuver themselves into its path can spare themselves the trek back from White Hole Station. This gravity lift will helpfully deposit the player at Riebeck's camp, which offers a campfire, oxygen, and a fuel tank.
- With lots of luck or skill, you can make various jumps below the surface that traverse almost half of the planet