Courtesy of the British Library

Ronald McGovern described himself as an “archaeologist,” but most experts preferred the term grave robber. Between 1900 and 1910, McGovern traveled the Middle East in search of antiquities. He stole hundreds of sacred carvings and sold them in Europe for a tidy sum.

Satisfied with his profits, McGovern planned to return to his native Baltimore and open a department store. But then he heard a rumor about a network of tunnels beneath the city of Rome, which might possess “the apostles’ treasure.”

Although McGovern grew up Presbyterian, and he claimed to carry a Bible everywhere he went, he did not seem to consider the strangeness of this—that the Twelve Apostles would have amassed any kind of treasure, much less hidden their trove in the Roman capital.

(Some contemporaries suggested that McGovern didn’t believe that the treasure came from the Twelve Apostles, per se, but that the name was shorthand for moneys collected by early Christians and stored underground).

Instead of keeping his expedition quiet, McGovern alerted the Italian press and even gathered reporters at the Trevi Fountain, where he made a speech and posed for photographs.

“If there is ever treasure to be found,” he declared, “you may rest assured that I will always be the one to find it.”

McGovern entered the Roman tunnels on April 2, 1911, with three other men. None of them were ever heard from again.

But for weeks afterward, Roman authorities received unsettling reports from city residents—specifically about their kitchen sinks. In homes with running water, spouts would spurt liquid the color of diluted blood. Some taps ejected fingernails and bone fragments, and one housewife reported a severed pinkie toe in her washbasin.

After reviewing the evidence, investigators did not turn up any identifying traces. The fate of McGovern’s team is still considered a mystery.