Colton brings Terry Deveau and Paul Troutman a core sample from Borehole DN12.5 at 88 feet, but Terry finds nothing out of the ordinary. The team is tracking a tunnel heading north toward the Garden Shaft that contained wood dating from as early as 1640. When Rick Lagina and Craig Tester arrive, a sample from 98 feet reveals pieces of wood that Paul identifies as a possible post or beam. Rick suggests Craig get a water sample from the borehole to test for precious metals.
In Royston, England, Marty Lagina, Alex Lagina, and Charles Barkhouse meet researcher and author Gretchen Cornwall at Royston Cave. Founded in 1184 and once part of the Roman Empire, Royston is home to a cave first documented in 1742 but believed to have been constructed during medieval times. Gretchen describes it as a Templar initiation chamber, disguised beneath a market stall, with walls covered in carvings. The center circle measures close to 13 feet, a dimension Marty notes matches the original Money Pit diameter. The group discusses similarities to what they observed at Sintra. Gretchen points out a carving she believes depicts the figure portrayed on the lead cross found on Oak Island, noting the tilted head and the longer arm on one side, details that also echo a carving found in the Templar prison at Domme, France. She then shows them a brick inscribed with the number 1347, the same date that appeared on Zena Halpern's map, which Marty suggests could be a commemorative stone marking the Templars' departure. Gretchen identifies another carving as a representation of Melusine, a half-human, half-fish goddess from the sixth century whom the Rochefoucauld family claims as an ancestress. She shows the group a photograph from the Château de Rochefoucauld where Melusine holds up a platform for a bust. Alex points out that a connection to the Rochefoucaulds would be another link to Zena's map.
On Lot 7, Gary Drayton and Jack Begley search an area recently cleared but not yet detected. At the first flag they unearth what Gary thinks could be a cloak pin or brooch, found near the spot where a garnet brooch was recovered in 2017. At the Interpretive Center, archaeologist Laird Niven examines the piece under a Fisherbrand 425 zoom stereoscopic microscope capable of magnifying up to 50 times. Rick points out a dark blue stone resembling sapphire. Laird suggests using the CT scanner, cleaning the piece, and then running the XRF to identify the metal and the jewel.
At the National Archives in Kew, Marty, Alex, and Charles meet historian Paul Stewart, who has found capture documents connecting the Duc d'Anville to Mahone Bay. Paul shows them records of The Lively, a ship captured near Nova Scotia in early 1746 by one of d'Anville's squadron. Because the capture document from January 1746 was signed by the Duc d'Anville himself, Paul believes he was present in the area and could have made several trips to Nova Scotia, supporting the partial ship's log found by Doug Crowell describing treasure buried on a small wooded island in September 1746. Paul then presents documents showing Admiral George Anson, a member of the British Navy during the 18th century, was targeting French ships associated with the September 1746 mission. Anson captured The Diamant and imprisoned its captain, Hocquart, to question him about activities in Mahone Bay. Letters requesting Hocquart's release include one that appears to be from the Rochefoucauld family. Alex observes that this information could explain why both British and French artifacts have been found on the island.
In the War Room, the team meets by video conference with Marty, Alex, and Charles in England. Alex describes Royston Cave as a hand-dug Templar chamber beneath the city, walks the team through the carvings, and shows photographs of the cross resembling the lead cross, the brick dated 1347, and the figure matching the Rochefoucauld coat of arms. Rick says it reminds him of the fish on Zena's map. Marty then shares the information from Kew about the Duc d'Anville's activity and the British interrogation of prisoners. Gary closes the session by showing the artifact he and Jack found on Lot 7.
