The team supervises the drilling of Borehole A.5N13.5, chosen based on water testing results and the possibility of tunnels related to the Garden Shaft. Terry Deveau tells Alex Lagina they are at 18 feet and still shallow as the team works to track the tunnel found two weeks ago at a depth of 103 feet, a tunnel that sonar showed heading north toward the Garden Shaft. Later, Marty Lagina, Craig Tester, and Rick Lagina arrive as Mike and Colton report that at 55 feet the bottom dropped out and felt hollow. By 85 feet they have passed through a ten-foot void located just three feet from Borehole AB13, where air erupted at 60 feet the previous season. Marty suspects an offset chamber may be nearby and orders a water sample from the borehole for testing. At 108 feet the soil is firm at the top but becomes loose as though it is nearing a structure, though there is no wood. Then bubbles begin rising to the surface of the water inside the Garden Shaft, suggesting the tunnel systems underground could be connected. Steve Guptill and Paul Troutman collect water samples from the shaft for Dr. Ian Spooner to analyze. On a later visit, Paul tells Rick and Marty about the air bubbles that appeared when drilling reached a depth of 108 to 115 feet.
At the Research Center, Rick, Gary Drayton, and Billy Gerhardt meet gemologist Peter Schneirla, who has more than 40 years of experience and has worked with the Smithsonian Institute, DeBeers, and Tiffany and Company. Peter examines the artifact found the previous week by Gary and Jack Begley on Lot 7, near where a garnet brooch was discovered five years ago and where a bunk hook and possible coin were found this season. Peter identifies a ferrous metal mounting around a glass jewel, with what could be a hinged cover, and describes the piece as a type of pin. Using the Fisherbrand 425 Series microscope, he points out an air bubble in the stone, noting that air or gas bubbles do not occur in any gem material except rarely in amber. Peter dates the style to the 1700s or earlier, calling the mounting unlike anything he has seen. Rick notes that in 2018 he and Gary found a brooch on Lot 21 that also contained a glass stone, which gemologist Charles Lewton-Brain said was not modern and used an ancient wire-making technique.
On Lot 8, Gary and Jack recover two pieces of folded copper that were bent over the edge of something and will need to be scanned, followed by a curved iron piece they think could be bell metal. The previous year the team found bell metal on Lot 4 that Dr. Christa Brosseau confirmed was used by the Spanish and Portuguese to make cannons.
Jack arrives on Lot 32 with Robert Seddon and Keith Hollender of Phoenix Aerial Productions, who will conduct a LIDAR scan of the island to detect trails, stone paths, and metal beneath the ground. After scanning Lot 32 the team will also cover other parts of the western side of the island. At the Interpretive Center, Gary and Charles Barkhouse meet with numismatist Sandy Campbell, who examines the possible coin from Lot 7. Sandy tells them the piece is not a traditional coin shape and without any visible detail it is more likely a barter piece, at least 500 years old. At the Research Center, Gary and Charles share Sandy's findings with Rick and Marty. Doug Crowell adds that the metal mixture shows it was used as far back as the 5th millennium B.C.
In the War Room, the team meets by video conference with Dumas Contracting to discuss the Garden Shaft restoration. Cameron Carter, Vice President of Engineering, presents the plan: Dumas will build a foundation, remove backfill, and reline the shaft while injecting grout into the surrounding soil to slow water intrusion. Probe drilling will check for voids as work progresses, and if a void is found Dumas can tunnel out to allow the team to explore. The plan calls for excavation and restoration to a depth of 77 feet over approximately 50 days.
