There have been plenty of archeological digs in Boston’s historic North End, but this is the first one in search of hidden treasure.

The scene took place at the baseball fields at Langone Park / Puopolo Field on Commercial Street as featured on this week’s season finale of Discovery’s Expedition Unknown. The TV crew followed the story of Jason Krupat and his family who figured out a puzzle from a 1982 book, The Secret, leading the clue-seeking treasure hunters to stop the construction at the waterfront parks.

The Secret book described twelve locations in cities around the country, but only two of the treasure jewels have been found in nearly 40 years since the book was published. Each treasure box has a key that can be turned in for a precious gem with a value estimated at $1,000.

Hot on the trail!@joshuagates is headed back to one of his favorite cities to reveal a secret that's been buried there for 37 years. Can you guess where? #ExpeditionUnknown pic.twitter.com/CmFk3OY2pA — Discovery (@Discovery) October 25, 2019

The Secret puzzle book includes 12 poems and 12 elaborate paintings by renowned fantasy illustrator, John Jude Palencar. In the North End, the painting matched that of the Christopher Columbus statue at the namesake park on Atlantic Avenue. The book’s author, Byron Preiss, looked to celebrate immigrants groups, including Chicago’s Irish, Cleveland’s Greeks and now, the Italians in Boston’s North End.

.@JoshuaGates is on the verge of finding a new piece of the puzzle that no one has cracked for nearly 40 years: The Secret. 🗝



Join the real life treasure hunt next Wednesday at 9p in the #ExpeditionUnknown season finale event on Discovery and the Discovery GO app. pic.twitter.com/qvm8vMaRC1 — Discovery (@Discovery) October 24, 2019

Game and puzzle designer, Jason Krupat, works in downtown Boston and had long suspected the clues referred to Paul Revere’s ride. The book said, “Face the water with back to the stairs” leading him to the ball fields opposite Copp’s Hill Terrace. That also matched the location where Paul Revere rowed from the North End to Charlestown, leaving from what is now Langone Park.

When Krupat saw the construction at the site for the ball field’s renovation, he went to the city’s construction crew. They dismissed it at first, but then found the treasure box near home plate at Puopolo Field in the North End. That led to the calls to Discovery Channel host Josh Gates and the filming of the TV episode re-enacting the find.

Hidden treasure, a family’s quest, and “The Secret” https://t.co/8CHszVbtm3 — The Boston Globe (@BostonGlobe) October 25, 2019

So, where are the remaining boxes? According to those hunting the clues, there appear to be jewels hidden in San Francisco, Charlestown, Houston, New Orleans and perhaps Montreal.

The full episode of the hunt in Boston’s North End will be available for online viewing shortly at the Discovery Channel’s Expedition Unknown website.