Entry 01 — 21 August 1986

Unexplained

The lake that exhaled.

Lake Nyos · Northwest Cameroon

On a Thursday evening a crater lake released a cloud of carbon dioxide that had been dissolved in its depths for decades.

Because CO₂ is denser than air it did not disperse. It rolled downhill through the valley, roughly fifty metres deep, into villages where people were going to bed. 1,746 people and 3,500 livestock died. Most never woke. Survivors came round from comas lasting up to thirty-six hours and found everyone they knew on the ground.

The lake is still there. It is still full. The engineers have put pipes in it, and they are reasonably confident.

What has never been established is the trigger. A landslide, a small eruption on the lake bed, a cold night — the record carries all three and settles on none. The lake was saturated and would have gone eventually. Nobody can say why it went then.

Entry 03 — 1 December 1948

Unexplained

Every label had been cut out of his clothes.

The Somerton Man · Adelaide, South Australia

A well-dressed man was found propped against the sea wall at Somerton Park, dead, with a half-smoked cigarette on his collar.

He carried no wallet, no papers, no identification of any kind. Every manufacturer’s label had been removed from his clothing. Nobody came forward. His photograph ran in newspapers across the country and not one person recognised him.

Months later a pathologist found a fob pocket sewn inside his trouser waistband that everyone had missed. Inside was a scrap of paper torn from the last page of a book, printed with two words in Persian: Tamám Shud. It means ended.

The book it came from turned up in the back of an unlocked car parked nearby. Pressed into the back cover were five lines of capital letters. Cryptanalysts, including military code-breakers, have never got anything out of them. A phone number was written there too, belonging to a nurse who lived minutes from where he was found, and who denied knowing him until the day she died.

In 2022, DNA finally gave him a name. It did not give anyone a reason. Why he died, what the letters mean, and why he tore that page out are exactly as unknown as they were in 1948.

Entry 05 — December 1900

Unexplained

The light had gone out, and so had they.

Flannan Isles · Eilean Mòr, Outer Hebrides

A passing steamer noticed the lighthouse was dark. It was eleven days before anyone could get out there to find out why.

The relief party found the entrance gate shut and the doors closed. The beds were unmade. The clock had stopped. The ashes in the grate were cold. A meal had been left out. Of the three keepers — Ducat, Marshall and McArthur — there was no sign at all, and the last entry in the log was made eleven days earlier.

Two sets of oilskins were missing. The third was still hanging up. In December, on that rock, going outside without it was not something a keeper would do unless he was leaving in a hurry.

The west landing was wrecked. Ropes torn away, iron railings bent flat, a block of stone weighing over a ton shifted from its place. The likeliest reading is that a freak sea took all three while they were trying to secure the gear, and that the third man ran out after the other two without stopping for his coat.

The log entries you may have read about — the storm, the weeping, the praying — were written by a poet twelve years later. The real log recorded nothing unusual. That is the part nobody likes.

Entry 07 — July 1518

Unexplained

Four hundred people who could not stop.

The dancing plague · Strasbourg

A woman stepped into the street and began to dance. She did not stop. Within a week dozens had joined her; within a month the city records describe around four hundred people dancing in the streets.

The authorities consulted physicians, who concluded this was a natural fever of the blood that had to be danced out of the body. So the city built a wooden stage, cleared a guildhall and hired musicians to keep them going.

Contemporary accounts describe dancers collapsing from exhaustion, stroke and heart failure. Ergot poisoning and mass psychogenic illness are both offered. Neither accounts for all of it, and the records are too thin to settle it.

Every person in that square had somewhere else to be. None of them could leave.

Entry 09 — 8 February 1855

Unexplained

Something crossed the county in one night.

The Devon footprints · South Devon, England

Snow fell overnight across South Devon. In the morning, people in a string of villages opened their doors onto a single line of hoof-shaped prints.

They were small, roughly four inches, evenly spaced, and in single file — one in front of the other, as though whatever made them had two legs rather than four. They ran through gardens and across fields. They went over haystacks. They went up and over rooftops and came down the other side without breaking stride. They appeared on both banks of an estuary.

Badgers, mice, otters, an escaped kangaroo, a hoax, a weather balloon trailing a shackle: every one of these has been proposed, and every one of them fails on the same point, which is that the line does not deviate for anything in its way.

The newspapers of the time put the distance at a hundred miles, and that figure is almost certainly too large. Nobody has ever credibly explained the part that is not disputed, which is the roofs.

Entry 11 — the usual version is wrong

Disputed

The lake does not turn you to stone.

Lake Natron · Northern Tanzania

You have seen the photographs: a bat, a dove, a fish eagle, grey and flawless, posed as though still alive. The story attached to them is that the water petrifies anything that touches it. It does not — Africa Check has formally debunked that framing. This is a hyperalkaline soda lake that slowly encrusts and mummifies animals already dead, and the photographer found the bodies washed up on the shoreline and arranged them on branches himself. He never claimed otherwise.

What is left once the story is stripped out is worse. The chemistry preserves detail down to the individual hairs on a bat’s face. And roughly three quarters of the world’s lesser flamingos choose to breed there — precisely because almost nothing else will follow them in.

What is still unexplained is how the birds end up in it. The best guess is that the surface reflects the sky so perfectly that they fly straight into it, believing there is nothing there.

Entry 13 — February 1959

Unexplained

They cut their way out of the tent from the inside.

Dyatlov Pass · Northern Urals

Nine experienced hikers. The tent was found slashed open from within and abandoned. They had gone out into roughly minus twenty-five degrees in socks and underclothes, and walked, not run, downhill toward the treeline.

The injuries are what keeps the file open. A fractured skull. Crushed ribs with no external wound, described as requiring a force comparable to a car crash. Soft tissue missing from one of the bodies. Traces of elevated radiation on some clothing.

In 2021 a slab-avalanche model was published that plausibly accounts for the chest and skull injuries and for the flight from the tent, and it is the strongest explanation anyone has produced. It does not close every detail, and the people who have read the original case files are not unanimous.

They were competent. They were equipped. Something made going out into that, barefoot, the better option.