The Six Zones of Pyros

The Black Rock — Sea Level Landing

The boat touches Pyros at a shelf of black basalt that juts above the waterline on the island's western face. There is no beach here, no gentle approach — only the rock, the sea, and the Tohu standing above it, already counting. The rock is slick at the waterline, rough higher up, and honeycombed at its base with caves the sea has carved.

This is where the Tohu performs the second count: not how many came, but how many will finish. In thirty years of standing on this rock, no Tohu has needed both hands for that number.

Above the rock, the black sand beach extends north and south for perhaps 400 metres before the glass begins. The sand is fine, dark as coal, and warm underfoot even at first light. The velu grove starts here at the southern end. The Lodge is a 20-minute walk from the landing, on the edge where the sand gives out.

The Lodge & The Green Belt

The Lodge is the last soft place on Pyros. The company maintains it well: cold drinks, woven chairs, a long open room with the sea in every window. The briefing takes place here — the lume assignment, the five-day window, the company man's careful language for the things that are going to try to kill you, and the Tohu's heavier, more honest version of the same.

Above the Lodge, the black sand runs out. Above that, the glass begins. A line of demarcation exists around 180 metres elevation where the Phlogiston-V gas begins to concentrate. You cannot see it. You cannot smell it. The light just begins to behave strangely — a shimmering that is not quite heat shimmer, because it sits still rather than rising.

One tip from the Tohu, worth more than any gear the company sells: learn the smell of velu before you leave the Lodge. There is a bowl of fruit on the company's table. Take the yellow one, bite it, and hold that sourness in memory. Then, on the third day, ask yourself if you can smell something similar but richer, sweeter, turned. If you can, and if you notice it arriving around your own face, stop walking immediately.

The First Glass Field

Elevation: 180 m — 900 m  |  Day 2 territory

The black sand gives out and the glass begins. The First Glass Field is where the mountain makes its first serious point: the obsidian scythes stand waist-high initially, then shoulder-high in the upper reaches, leaning uniformly in the direction of the original prevailing wind — which is to say, toward you. Each blade is curved, sharp on every edge, and reflective: on a clear morning the field throws the sun back doubled. Climbers emerge from the glass fields with blood from cuts they did not feel while they were bleeding.

The Phlogiston-V gas layer sits above the transition point between Zones 2 and 3 — approximately 220 metres elevation. Once you cross that line, the mountain can taste you. The rule from the Tohu: small breath, through the nose, slow. The mouth is a door. Keep the door small.

Drones fail in Zone 3 within two to three hours. The acid the mountain breathes corrodes filters, sensors, and electronic housings progressively from the moment you enter the gas layer. By the end of the first day on the glass, most electronic equipment is degraded or dead. The exception is the lume — the blood-oxygen reader the company issues — which is sealed in ceramic and built specifically to survive. The mountain eats your eyes. It leaves you your clock.

The Deep Glass

Elevation: 900 m — 2,200 m  |  Day 3 territory

The slope tilts until it is less a slope than a wall. In the Deep Glass, climbing becomes a sideways affair: the scythes are taller than a person, the gaps between them narrow, and movement through them requires turning the body sidewise and threading it through the blades. The face of every scythe is a mirror. The face of every mirror holds a fragment of your reflection, stretched and slid along beside you. The hunters who have climbed the Deep Glass uniformly report that they stopped looking sideways after the first hour. The mirrors show you something you do not want to see when you are frightened.

The Deep Glass is where the packs come open. A pack that felt manageable at the Lodge is an anchor in Zone 4 — because the blood has been thinning since Zone 3, and thinned blood cannot carry weight the way healthy blood can. Gear gets jettisoned here: spare boots, stoves, folding tools, second coats. The slope behind a climbing party fills slowly with their shed and shining skin.

The Crust

Elevation: 2,200 m — 2,900 m  |  Day 4 territory

After the vertical effort of the Deep Glass, the Crust arrives like a kindness: a long, gently domed plain of pale obsidian, almost flat, smooth, quiet under the sun. The hunters see it and their shoulders come down. This is a mistake.

The Crust is a roof. Under it, the old lava tubes — where flows once ran and then drained — create hollow channels of unknown depth. The glass over them cooled to a skin: in some places an arm's breadth thick, in others no more than a dinner plate. A single person, light and careful, stepping precisely where the Tohu's feet have said yes — can cross it. A person carrying excess weight, or moving quickly, or stepping wide of the marked print — cannot.

The Crust does not crack when it fails. It turns from floor into air: a section the size of a small room will simply cease to be there, without warning, without sound until the sound of it is already behind you and below you. The Long Span — a 40-step bridge of crust over the widest tube — is the most dangerous single passage on the standard route.

The Vent Zone

Elevation: 2,900 m — 3,400 m  |  Day 4 afternoon

The Vent Zone is the only part of Pyros that does not judge you. Every other hazard on the mountain is personal: the gas responds to your history, the crust responds to your weight, the glass responds to how carefully you have learned to listen. The vents respond to nothing. They breathe because the furnace below is breathing, on its own schedule, without reference to anything happening on the surface.

Fumaroles and seams open and close across the upper slope. When a vent exhales, the vapor comes down the rock the way water comes down a window — fast, spreading, carrying the concentrated acid breath of the mountain's interior. It smells, before it hits you, almost pleasant: a sharp mineral sweetness. That is the last thing you smell clearly. After that, the eyes close, the chest forgets the rule about slow breathing, and everything is yellow.

The Tohu's protocol for a vent encounter: down immediately, every person's hand on the next person's shoulder, eyes shut, mouth shut, breathe through the shirt fabric, move as a chain toward clean air. Do not let the chain break. If it breaks, the person lost will try to save themselves by moving faster, and moving faster means deeper into the yellow.

The Sieve — Valley of Fire

Elevation: 3,400 m — 3,700 m  |  Day 5 morning

The Sieve is a long, shallow bowl of obsidian lying just beneath the crater rim — the last ground between the ascent and the prize. It is filled, brim to brim, with Phlogiston-V at its highest and oldest concentration. There are no thin places in the Sieve. The whole valley is awake and tasting.

The air above the Sieve does not shimmer the way hot air shimmers. It boils — slow, silent, visible as a distortion through which the far rim seems to swim like a stone seen through water. A body carrying any metabolic trace of vice walks into this valley and provides the gas with everything it needs. A body that carries none — the clean body, the empty body, the body pointed entirely at something beyond itself — provides the gas with nothing, and the gas parts around it.

There is one documented instance of a climber with a lume reading of 58 — nearly 12 points below the company's safety threshold — crossing the Sieve clean. The Tohu's explanation, offered years later, was not about metabolic chemistry. It was about direction.

The Rim & The Crater

Elevation: 3,847 m (rim)  |  Day 5 midday

The rim is the end of the ascent and the beginning of the descent into the prize. It is a narrow ring of solid rock around the caldera's edge, with a straight fall on the inner side of approximately 300 metres to the caldera floor. At the rim, for the first time in five days, a climber can look down at Maloa's Blood.

The tree grows on the caldera floor in a tangle of its own black stilt-roots, braced against the black walls on three sides. Its fruit — a dozen or so on a mature tree, each a sphere the size of a sleeping child, armoured in obsidian-glazed plates — hang heavy in the root tangle. In the red light of the crater they throw the light back like struck jewels. The red light of the crater is real: the residual magmatic heat gives the caldera air a warmth and a colour. The effect, for a person arriving at the rim after five days of black and silver, is very difficult to describe without borrowing the word holy.

The descent into the crater takes roughly two hours. The ascent from the crater to the rim, after drinking, takes somewhat less — the fruit goes to work quickly. Camp on the rim, keep water. The descent off the mountain, after the crater visit, runs roughly six to eight hours depending on conditions. Expect the mountain to have changed during your absence. It usually has.