Echoes of the Unknown

In today's episode, we’re traveling back to New York City in the winter of 1910, when a young woman from one of Manhattan’s wealthiest families stepped out of her home for an ordinary afternoon of shopping. She was seen buying chocolates. She stopped at a bookstore. She spoke casually with a friend on Fifth Avenue. And then, somewhere among the crowded streets of one of the largest cities in the world, socialite and heiress Dorothy Arnold simply vanished.

In today's episode, we’re traveling back to the dawn of motion pictures and the story of a largely forgotten inventor who may have been on the verge of changing the world. In 1888, Louis Le Prince captured moving images with a camera of his own design, years before motion pictures became a worldwide phenomenon. But just as he was preparing to publicly demonstrate his invention, he apparently boarded a train in France — and vanished without a trace.

In today's episode, we’re traveling back to the Chicago suburbs in 1982, when seven people died after taking Extra-Strength Tylenol that had been deliberately laced with cyanide. Most of the victims had no connection to one another, and the killer never had to confront them directly. Instead, poisoned capsules were placed back on store shelves, turning one of America’s most trusted medicines into a murder weapon. To this day, the killer remains unknown.

In today's episode, we’re traveling to Vermont in 1946, where college student Paula Jean Welden set out alone for an afternoon walk in the Green Mountains. Several people saw her along the way, but after reaching the Long Trail, she disappeared. No confirmed trace of her has ever been found. Paula's disappearance would become one of Vermont’s most enduring mysteries — and the troubled investigation that followed would help change law enforcement in the state forever.

In today's episode, we’re traveling to California in 1978, where five friends set out together one Friday night. They drove to a college basketball game, stopped at a market for snacks, and began the trip home... but they never arrived. Days later, their car was discovered abandoned, high in the Sierra Nevada foothills, on a remote mountain road they had no reason to be traveling. Months later, four of the five men would be found dead under perplexing circumstances — the fifth would never be found.