The Zodiac Mailed One More Code. Never Solve It Alone.

In the summer of 1969, a killer in Northern California began writing letters to newspapers. He called himself the Zodiac.¹

With his letters came codes. Rows of strange symbols. Circles, triangles, backward letters, little crosses. He said that if the papers printed them, and someone solved them, they would learn who he was.²

The first code, 408 symbols long, was printed in the papers. Within about a week, a schoolteacher and his wife in Salinas, Donald and Bettye Harden, solved it at their kitchen table.³

It did not contain his name. It said he killed people because it was fun. And it said that the people he killed would become his slaves in the afterlife.⁴

In November 1969, the Zodiac mailed a second code to the San Francisco Chronicle. This one was 340 symbols long.⁵ Thousands of people tried it. Professional codebreakers tried it. Computers tried it. For fifty-one years, no one could read it.

In December 2020, three amateur codebreakers, David Oranchak in the United States, Sam Blake in Australia, and Jarl Van Eycke in Belgium, finally cracked it. The FBI confirmed their solution.⁶

It still did not contain his name. It said he was not afraid of the gas chamber, because it would only send him to paradise sooner, where his slaves would be waiting.⁷

The Zodiac has never been identified. Two of his shorter codes have never been solved at all.⁸

He once claimed he had killed thirty-seven people. Police have confirmed five deaths.⁹

Nate Kowalczyk worked nights in the basement of a newspaper archive. Fifty years of paper. Clippings, photos, letters to the editor. Most of it had never been scanned. His job was to scan it, one box at a time, while the rest of the building slept.

Box 1970-C was labeled Crank Mail. Letters from people who said they were Jesus, people who said the moon landing was fake, people who wanted to complain about the comics page.

At the bottom was an envelope nobody had ever opened.

It was addressed to the editor in blue felt-tip pen, in big, careful capital letters. The stamp was placed upside down. Nate had read enough about the Zodiac to know that he put his stamps on upside down, sometimes.¹⁰

His hands went cold.

Inside was one sheet of paper. Rows of symbols. Circles with crosses through them. Triangles. Backward letters. Under them, in plain English, one line:

PRINT THIS ONE AND IT IS NOTHING. A CODE SOLVED BY THOUSANDS BELONGS TO NO ONE. A CODE SOLVED BY ONE MAN BELONGS TO HIM.

Nate knew exactly what he should do. Call the editor. Call the FBI. Hand it over. Let the experts and the newspaper and the world work on it together, the way they had worked on the 340.

But Nate had read about the three men who solved the 340. He had seen their faces in the news. He had thought, more than once, that could have been me.

He was thirty-four. He scanned paper in a basement. No one had ever put his face in the news.

He photographed the sheet. He put the envelope back in the box, at the bottom, where it had been for fifty years.

He would solve it himself. Then he would tell the world.