A team of Americans attempts to solve one of the great mysteries of World War II. With the help of an eyewitness, they explore a mountain in the Philippines where Japanese general Yamashita is believed to have buried a vast treasure during the war.

Digging continues at Breach-6, but when the team unearths a possible water trap, excavation is put on hold. To find another way into the mountain, the team conducts a LiDAR scan that reveals a cave, perhaps used by Japanese soldiers during the war.

After discovering a bomb marker, the team brings in an explosives expert to search a cave that may have been a headquarters of General Yamashita during the war. Inside, they uncover a potential booby trap, along with their first hint of treasure.

The team triggers a possible water trap in the cave and are forced to stop digging. Martin Flagg believes the Story Rock indicates a tunnel behind a waterfall and the team brings in a Navy diver to explore the plunge pools and search for an entrance.

Unable to find a tunnel at the waterfall, the team is guided by an animal marker to a boulder carved in the shape of a turtle. Following the direction of the turtle head, the team discovers a Golden Lily symbol indicating a secret backdoor entrance.

The team attempts to prove if a tunnel exists behind a unique formation of rocks they believe is a secret backdoor entrance into the mountain. Battling a typhoon and possible Nazi concrete, the team ultimately finds proof of a void 40 feet below.

As the team zeroes in on a tunnel that may be part of the treasure labyrinth, Bingo learns that part of dictator Ferdinand Marcos' fortune may have been stolen from Yamashita's Treasure and uncovers a possible link to a CIA conspiracy.

Peter meets with a man who warns of the deathly risks of searching for Yamashita's treasure, and a connection to the CIA, as the team moves mountains to clear the last obstacles and finds a secret tunnel directly into the mountain.

American treasure hunter John Casey returns to the Philippines with a new team and new technology, in a continued effort to solve one of World War II's greatest mysteries. A satellite scan of the mountain reveals massive metal deposits underground.

With new evidence suggesting the location of a possible treasure vault beneath the waterfall, John is determined to find a way in, but mother nature is wreaking havoc on his plans. Meanwhile, a clue uncovered at Breach 6 has the team going all in.

Exploration of the tunnel is put on hold after an explosive find. Meanwhile, as John hits a roadblock on his search for a tunnel entrance near the waterfall, Bingo makes an incredible discovery that could lead him to Golden Lily treasure maps.

Left with no other option, John plans to drill across the mountain to get underneath the waterfall. Meanwhile, Rick finds an artefact at Breach 6 that could confirm Japanese military presence on the mountain during World War II.

While John and Rick work to decipher a Golden Lily map, Breach 6 reveals its first piece of treasure. Meanwhile, Levi and Geo come up with a creative solution to get past a mysterious collapse in the tunnel.

The quest for the one of the largest treasures in modern day history continues. The Lost Gold of World War II returns to resume the search for hundreds of billions of dollars of stolen loot supposedly hidden by Japanese General Tomoyuki Yamashita.

When a dead end in the tunnel threatens to close the door on exploration, a back door opens. Using their recently decoded Golden Lily map, the team discovers new access points, hoping to get under the waterfall by any means necessary.

The quest for the one of the largest treasures in modern-day history continues. The Lost Gold of World War II returns to resume the search for hundreds of billions of dollars of stolen loot supposedly hidden by Japanese General Tomoyuki Yamashita.