Setting chronology · Year 0 to Year 1200

The Thousand Years

From the day the depot opened its overflow valve to the morning the Mariner sails into frame — forty-eight generations, eight thousand meters of water, and a machine that never once malfunctioned.

Flood duration: 1,000 yr
Total rise: +8,150 m
Peak rate: 11 m/yr
Peak rainfall: 16 m/yr
Salinity: 35 → 29 ‰
Film opens: Year 1200

How to read this

Year 0 is the day the overflow procedure begins, about two years into the collapse. A generation is 25 years. Sea level is meters above the pre-deluge datum. At +8,150 m, eight summits still stand out of the water. Everest stands 699 m out.

Read the rainfall figures as how much it rains, not how much arrives. They include water evaporated off a warmer, all-ocean planet and rained out again.

The rate is not constant. The depot vents conservatively at first, ramps as the backlog of unshipped cargo grows, peaks for three centuries, then tapers as the inbound stream fails and the backlog drains.

The rain got worse for four hundred years before it got better, and nobody alive at the time could have known that.

Hover or use the arrow keys to read any year. Bands mark the seven eras. Population is one figure per era, plotted at the era’s midpoint.

Show the numbers

Era	Years	Gen	Sea level	Rate, m/yr	Rainfall	Salinity	Population
I. The Quiet Years	0–40	1–2	+60 m	1.5	+2	34.8 ‰	380 M
II. The Drowning	40–140	2–6	+1,160 m	11.0	+16	34.0 ‰	160 M
III. The Building	140–320	6–13	+3,100 m	10.8	+15	32.5 ‰	28 M
IV. The Sunless Century	320–520	13–21	+5,300 m	11.0	+16	31.2 ‰	1.2 M
V. The Shrinking	520–800	21–32	+7,350 m	7.3	+10	29.8 ‰	350 K
VI. The Last Mountain	800–1000	32–40	+8,150 m	~4, then a stuttering stop	+6, then 0	29.0 ‰	160 K
VII. After the Rain	1000–1200	40–48	+8,150 m	0	natural	29.0 ‰	60 K

Era I · Years 0–40 · Generations 1–2

The Quiet Years

+60 m · 1.5 m/yr · rain +2 m/yr · 34.8 ‰ · 380 M people

The plague has burned out. What is left of the world is busy burying its dead and arguing about who is in charge, and the rain is simply weather: heavy, persistent, getting worse, and explained by everyone in a way that is not the truth.

The depot opened its overflow valve in the second year of the collapse. Conservatively. Exactly as specified. A temporary measure, pending supervisor review.

A meter and a half a year reads as a bad decade to a civilization that has just lost nine tenths of its people. The deltas go first — Bengal, the Nile, the Mekong, the Mississippi — and they were already going.

+60 m by Year 40. Of the whole flood, that is this much: 0.7%.

Year 5+8 mBengal, the Nile delta, the Mekong, most Pacific islands
Year 22+33 mFlorida, the Netherlands, Shanghai, London, New York

Hook. Somewhere in this era is the last person who understood the depot and could have countermanded it. They die of something ordinary. In this book, that person is the founder of the line, and somebody did write it down.

The line Year ~20 · Up

Era II · Years 40–140 · Generations 2–6

The Drowning

+1,160 m · 11.0 m/yr · rain +16 m/yr · 34.0 ‰ · 160 M people

I II III IV V VI VII VIII IX X XI XII Year 61

One year of the Drowning, marked monthly on a wall. Eleven meters a year is about 0.9 m between marks.

Eleven meters a year is a meter a month: a line you can mark on a wall and watch reach it.

The rate climbs and does not stop climbing. Every port, every coastal plain, every city that ever mattered. The refugee movement is the largest in history and it has nowhere to go but uphill, and uphill is already occupied by people who got there first.

This is also the era of the false spring. Drowning continents dump an extraordinary pulse of nutrients into the sea, soil and forests and whole cities of organic matter, and the ocean blooms. A generation learns to live on the water during the richest fishery in the history of the planet, and concludes that the sea will provide.

It will not. The pulse is finite and it is already being buried. Every productive fishing ground humans ever used sat on a continental shelf in less than 200 m of water, and those shelves are now 1,300 m down and dark. The new shallows are drowned mountainside: bare rock, no sediment, nothing.

And this is where scurvy kills everyone who still cooks. The survivors are the ones who learn to eat fish raw and organs first. That change, from cooked food to tearing open a fish for the liver and the eyes, is the cultural break, and its taboos outlive the reason for them by a thousand years.

Drowning land feeds the sea
The richest fishery in planetary history
The pulse is buried
Bare drowned mountainside

Year 55 · +225 mThe Amazon basin becomes an inland sea; the North European Plain
Year 75 · +445 mThe original shelves go dark; new shallows now drown too fast to colonize

Hook. The last harvest generation and the first water generation are alive at the same time and cannot speak to each other. The old ones are starving on principle.

The line Year ~90 · Out and back

Era III · Years 140–320 · Generations 6–13

The Building

+3,100 m · 10.8 m/yr · rain +15 m/yr · 32.5 ‰ · 28 M people

The last coordinated thing the species does. Enough industry survives in the highland cities — Denver’s successors, the Mexican altiplano, Addis, Lhasa, the Andean spine — to build floating habitat at scale. For six generations it is the great project: buoyancy cells rated for centuries, desalination cores, growing decks, hulls that will not rot.

Every atoll in the film has one of these at its heart. What the audience sees, the welded scrap, the nets, the patched plate, is five hundred years of patching around a core nobody can open and nobody can build. The atoll is not the junk. The atoll is the thing in the middle that makes fresh water.

Quality declines across the era, because capability does. Older atolls are better atolls, and everyone knows which is which. That is the political geography of the film’s world, and it is set here.

Parts list
Item	Description
1	Growing deck
2	Desalination core
3	Buoyancy cells, rated for centuries
4	Hull that will not rot

Revisions · what goes under while the yards work
Year	Sea	Under
182	+1,610 m	Denver
222	+2,050 m	Most of the Alps below the peaks; the Colorado Plateau
240	+2,240 m	Mexico City
277	+2,640 m	Bogotá
296	+2,850 m	Quito

Floating habitat · core section Era III · not to scale

Year ~140 The first yards launch structures a kilometer across. Year ~320 The last launch rafts with a pump.

Hook. Shipwright is the last real profession. Everything after this era is salvage, and the people who know it is the last era are the shipwrights.

The line Year ~200 · Out, one stays

Era IV · Years 320–520 · Generations 13–21

The Sunless Century

+5,300 m · 11.0 m/yr · rain +16 m/yr · 31.2 ‰ · 1.2 M people

The nadir. The yards fail: no ore, no power, no cities left to build them from. The last new hull is laid down and everyone present knows it is the last.

Peak rate, peak rain. Sixteen meters of rainfall a year, worldwide, is roughly 43 mm a day, every day, on every square meter of the planet. It is a permanently overcast, permanently dripping world. Nobody in this era has seen the sun as more than a bright patch.

The ozone layer is at its thinnest and stays there. This is the cataract generation: people going blind in their forties in a world that requires sight to eat. Folate collapses from both ends at once, destroyed by UV and absent from a diet with nothing green in it. A large share of pregnancies fail or end in neural tube defects.

Population falls by more than 95% across two centuries. Everything hard about the film’s world, the scarcity, the scavenging, the brutality, the drifter economy, sets here, because everything softer dies.

One year of the Sunless Century

43 mm of rain on each of 365 days, on every square meter of the planet.

Of every hundred people alive when the Sunless Century begins, about four are alive when it ends. 28 M → 1.2 M

Year 370+3,650 mLhasa
Year 447+4,500 mThe Tibetan Plateau, all of it

Hook. Three atolls agree to consolidate. Two arrive.

The line Year ~440 · Up, the last time

Era V · Years 520–800 · Generations 21–32

The Shrinking

+7,350 m · 7.3 m/yr · rain +10 m/yr · 29.8 ‰ · 350 K people

The rate is falling. The backlog is draining and the inbound stream is thinning, but there is almost nothing left to lose. The highland holdouts go under one at a time, and each is a small named apocalypse with a date.

Each drowning pushes a final wave of refugees onto atolls that cannot feed them. The atolls have learned what to do about that, and what they do is the reason nobody in the film trusts anybody.

This is the era of the last of everything. The last herd animal. The last standing forest. The last written archive, because by now there is nowhere dry enough to keep paper for a century.

On the Himalayan massif, the mountain begins to trade with the atolls: dirt, seed, wood and fiber down; metal and fish up. Dirt as the mountain’s export is the origin of the film’s dirt economy. The atolls learn that land exists. They never learn where.

Elbrus Year 567 · +5,640 m

Kilimanjaro Year 602 · +5,900 m

Denali Year 642 · +6,190 m

Aconcagua Year 747 · +6,960 m

The last herd animalno date kept

The last standing forestno date kept

The last written archiveno date kept

After Aconcagua, only the Himalaya and the Karakoram remain.

Hook. The massif takes in the survivors of a drowned plateau, including their books, and has to choose within a year between the books and the people. The books are lighter.

The line Year ~650 · Out and back

Era VI · Years 800–1000 · Generations 32–40

The Last Mountain

+8,150 m · ~4 m/yr, then a stuttering stop · rain +6 m/yr, then 0 · 29.0 ‰ · 160 K people

Only the Himalaya and the Karakoram are left, and they are becoming an archipelago. A few thousand people hold the summit massifs with the last working technology on Earth: reactors, laboratories, a seed bank, and the salvage of a civilization carried uphill for eight centuries by people who never intended to stop climbing.

They can do arithmetic. They know the water is slowing and they know it will stop. They do not know whether it will stop below them, and their error bars are wider than the mountain is tall.

So they spend their last two generations on the only project that makes sense. Not a weapon. A successor: gill-bearing, salt-tolerant, pressure-adapted, something that can outlive the last mountain. One cohort, small and late, released or abandoned around Year 960. The film’s Mariner is a descendant of that cohort, roughly eight generations down, and does not know it.

Then the rain slows, and stutters, and stops. It stops 700 m below the summit.

Schematic. The uncertainty on where the water would stop was larger than the part of the mountain still above it.

Year ~985Year 1000

The backlog drains in discrete cargo lots, so the rain does not fade. It stutters. Dry weeks, then a month of it, then nothing. Schematic.

They saw the rain stop. What they could not know was that it had stopped for good. The builders’ generation died waiting for it to resume. The next generation stopped waiting, stopped maintaining, and most of them left in the boats.

The leavers are how the water world has a Dry Land myth at all. The stayers are the line.

K2 carried its own holdout, 1,300 km to the northwest. It went silent in this era and became a rumor, even to the people who have a rumor.

Year 962+8,000 mFourteen islands left on Earth
Year 1000+8,150 mThe rain stops. Eight summits remain; Everest stands 699 m out.

The line Year ~950 · Out, most do not return

Era VII · Years 1000–1200 · Generations 40–48

After the Rain

+8,150 m · no rise · rain natural · 29.0 ‰ · 60 K people

A generation grows up in direct light and does not believe their grandparents’ descriptions of the gray.

The sky clears. The stratosphere dries out within a decade of the last delivery, ozone rebuilds over the following century, and the sun comes back.

The ocean slowly begins refilling its empty niches. Everything human keeps declining. The atoll cores are five to eight centuries old. Salvageable metal is nearly gone. Population settles near sixty thousand, scattered, with no path back up. The materials trap has closed and nobody has noticed, because nobody remembers a world with ore in it.

On the mountain, a few thousand become a few hundred become one family. The reactors run out of fuel. The boats wear out. The last hull dies around Year 1070, and after that nobody leaves and nobody arrives.

Five generations later, land is something a grandmother said her grandfather came from.

The film opens inYear 1200

The line Year ~1190 · Out

For dating any scene

What drowns when

The hypsometric ladder. Elevations are pre-deluge. Every row sits on the same flood curve as the chart above.

Era	Year	Sea level	What goes under
I	5	+8 m	Bengal, the Nile delta, the Mekong, most Pacific islands
I	22	+33 m	Florida, the Netherlands, Shanghai, London, New York
II	55	+225 m	The Amazon basin becomes an inland sea; the North European Plain
II	75	+445 m	The original shelves go dark; new shallows now drown too fast to colonize
III	182	+1,610 m	Denver
III	222	+2,050 m	Most of the Alps below the peaks; the Colorado Plateau
III	240	+2,240 m	Mexico City
III	277	+2,640 m	Bogotá
III	296	+2,850 m	Quito
IV	370	+3,650 m	Lhasa
IV	447	+4,500 m	The Tibetan Plateau, all of it
V	567	+5,640 m	Elbrus
V	602	+5,900 m	Kilimanjaro
V	642	+6,190 m	Denali
V	747	+6,960 m	Aconcagua. Only the Himalaya and Karakoram remain.
VI	962	+8,000 m	Fourteen islands left on Earth
VI	1000	+8,150 m	The rain stops. Eight summits remain; Everest stands 699 m out.

Kilimanjaro is placed on the flood curve at Year ~602, when the sea reaches +5,900 m.

Background, not plot

After the after

Any intelligence that evolves is born into the same materials trap: no fire, no ore, permanently pre-technological, waiting on geology for a shore it does not know is coming.

Years 1,000–1,200The rain stops. The film.
1 million yearsSpeciation and niche refilling, no new body plans. Explosive radiation from a small founder set: recognizable fish doing unrecognizable jobs.
10 million yearsGenuine novelty. For calibration, ten million years is roughly what it took to turn a wolf-sized land mammal into a fully aquatic whale.
50–100 million yearsLand returns. Hotspot shield volcanoes measure about 10 km from base to summit, so rare, short-lived volcanic islands come first. Continental collision brings back real land.

Next · Year 1200

The Drowned World

A salty sea, an empty sky, people without fire, eight rocks, and one fixed star.