The Timeline

Mysteries, operations, and open files — sorted by when they began.

A century of darker rooms, in order. Each file is anchored to the year it was set in motion — even those that ran on, or that we are still finding out about. Click any decade to jump.

142 files · 101 confirmed · 41 mystery · -9500–2030

Truth label

Region

1900s

The lighthouse on Eilean Mòr, the Flannan Isles, from which three keepers vanished in December 1900.

Mystery1900

The Flannan Isles: The Lighthouse Keepers Who Vanished

The Flannan Isles are remote islets in the Outer Hebrides, about 32 km west of Lewis. The lighthouse on the largest, Eilean Mòr, was manned in December 1900 by three keepers — Ducat, Marshall, and MacArthur. Around 15 December a ship saw the light was out, but the relief vessel, delayed by weather, reached the island only on 26 December. The relief keeper found it empty: the lamp ready but unlit, the clock stopped, the men gone, their bodies never found. At the exposed west landing, storm damage over 100 feet above the sea — ropes torn out, railings bent — pointed to a giant wave; two sets of foul-weather gear were missing, one left behind. The likely answer: a giant wave swept the men away as they secured equipment in a storm. A 1912 poem added fictional details that became the legend.

United Kingdom

The flattened Tunguska forest, photographed during Kulik's expedition around 1929 — millions of trees felled by a cosmic airburst.

Mystery1908–1927

Tunguska: The Cosmic Explosion That Flattened a Forest

The Tunguska event was an enormous explosion on 30 June 1908 over remote central Siberia — the largest impact event in recorded history. A cosmic body (most likely a stony asteroid) tens of meters across detonated several kilometers up in an airburst, releasing roughly 10–15 megatons — hundreds of times the Hiroshima bomb. It flattened about 2,000 square kilometers of forest in a radial pattern and lit bright nights across Europe, yet left no crater. So remote was the region, and so convulsed Russia, that no scientist reached it until Leonid Kulik in 1927; he found the felled forest but no crater or meteorite — the airburst signature. The missing crater bred fringe theories, but the consensus is a cosmic airburst. Tunguska is the defining warning of the near-Earth-object hazard.

Russia

1910s

The Latin Bridge in Sarajevo, beside the corner where Franz Ferdinand and Sophie were assassinated on 28 June 1914.

Confirmed1914

The Assassination of Franz Ferdinand: The Shot That Lit the World

On 28 June 1914, Archduke Franz Ferdinand, heir to the throne of Austria-Hungary, and his wife Sophie were shot dead in Sarajevo by Gavrilo Princip, a 19-year-old Bosnian Serb — one of several Young Bosnia assassins armed by the Black Hand, a society tied to Serbian military intelligence. A bomb thrown that morning had failed; the killing happened only through blunders — a wrong turn, the car stopping to reverse feet from Princip. It triggered the July Crisis: Austria-Hungary's ultimatum to Serbia, Germany's 'blank cheque,' and mobilisations that within weeks led to the First World War (~20 million dead, four empires gone). It was the spark, not the cause — the powder keg was alliances, militarism, and nationalism. A real conspiracy (the Black Hand); Serbian state complicity is debated.

Bosnia and Herzegovina

Charles Ponzi in 1920, at the height of his fame, promising to double his investors' money in ninety days.

Confirmed1919–1920

Charles Ponzi and the Scheme That Bears His Name

Charles Ponzi was an Italian immigrant who, in 1919–1920, ran a fraudulent investment scheme through his Securities Exchange Company in Boston. He promised 50% returns in 45 days, claiming to profit from arbitrage in international postal reply coupons — a real but hopelessly impractical mechanism. Almost no coupons were traded; he simply paid early investors with the money of later ones, the structure now called a 'Ponzi scheme.' Money flooded in — some $15–20 million from tens of thousands of people. The Boston Post and analyst Clarence Barron showed there were far too few coupons in the world to back the returns, and his own publicity man exposed him. A run and audit revealed total insolvency. Arrested in 1920 and deported, he died penniless in Rio in 1949 — but his name endures.

United States

1920s

The Hinterkaifeck farmstead, c.1922, where six people were murdered and the killer was never found.

Mystery1922

Hinterkaifeck: The Farm Murders That Were Never Solved

Hinterkaifeck was an isolated farmstead in Bavaria, Germany, where on 31 March 1922 six people were killed with a mattock: the farmer Andreas Gruber and his wife, their widowed daughter Viktoria, her two young children, and the maid Maria Baumgartner, on her first day. Beforehand, Gruber had reported eerie signs — footprints leading to but not from the farm, footsteps in the attic — but never told police. After the killings, the murderer appears to have stayed for days, feeding the animals; the bodies were found only on 4 April. Robbery was ruled out. A vast investigation examined 100+ suspects over decades — a neighbor, and the theory that Viktoria's husband, presumed killed in WWI, had returned — but no one was charged. One of history's most famous unsolved murders.

Germany

An open-pit asbestos mine at Amiandos, Cyprus, 1957 — the "magic mineral" the industry sold while knowing it was lethal.

Confirmed1924–2005

Asbestos: The Industry That Knew It Was Killing People

Asbestos — a fibrous mineral prized for fire resistance and used massively in 20th-century construction — causes asbestosis, lung cancer, and mesothelioma decades after exposure. The dangers were documented from the 1920s, and the major firms, led by Johns-Manville, understood them through their own sick workers. Internal documents later proved the industry concealed the risks, suppressed studies, and failed to warn workers, for profit. In 1964 Dr. Irving Selikoff's studies publicly established the cancer link. Litigation followed; Johns-Manville went bankrupt in 1982, creating a victims' trust copied industry-wide. Over 60 countries have banned it, but it is still mined and used elsewhere, and asbestos disease still kills 100,000+ a year — among the deadliest cover-ups in history.

United States