Vanessa Lucido inspects the area around TB1 after the previous day's cave-in. Tons of soil and gravel were used as backfill in an effort to stabilize the shaft. Marty Lagina suspects the natural seal over a void has been broken and material inside the caisson has dropped into it. Alex Lagina suggests they may have pierced the roof of a chamber or tunnel, and Marty wonders whether the team has collapsed into the treasure vault itself. Vanessa requests thousands of gallons of water to increase hydrostatic pressure and stabilize the shaft so the hammer grab can resume. The next day, Billy Gerhardt reports that 48 to 49 yards of crushed stone were poured down the hole before operations resumed. Vanessa confirms the shaft has reached 164 feet with no plug, but the caisson is meeting extremely hard material all the way around, which Terry and Marty interpret as the edge of the solution channel running between 160 and 180 feet underground. Another can and more water are added. By the afternoon, TB1 has reached nearly 170 feet. Alex recovers a piece of wood from the latest spoils that sinks when placed in water, a sign it could be very old. Vanessa reports a depth of 168 feet and six inches, with the casing at 171. After the War Room session, however, Vanessa shows Rick Lagina, Marty, and Alex that the collapse is continuing and moving beneath the crane. Terry confirms a depth of 179 feet. Vanessa explains that every 30 to 40 minutes the crew must pause to slow the collapse, and warns that if it extends further under the crane it will become a safety issue. Rick and Marty agree it is time to stop digging TB1.
In the northern swamp, Rick, Marty, and other team members continue searching for structures and artifacts. Alan Kostrzewa begins digging while Gary Drayton metal-detects the area. Gary picks up a hit, and Marty uncovers a piece of brick. Alan removes more dirt, and Gary notices a wooden stake, followed by a second one Rick spots nearby. Tom Nolan notes that stakes have been found on this side of the road before but not in this particular location. Rick asks Steve Guptill to take GPS measurements, and Steve confirms these stakes are in line with those found previously. Rick then notices cobble near the stakes and wants Dr. Ian Spooner to examine it. The following day, Alan unearths more cobble that Tom compares to the stone path. Scott calls Dr. Spooner and Laird Niven to take a look. When they arrive the next day, Alex suggests cutting a section, and Laird agrees.
In the lab, Marty and the team hear results on four nails recovered from the TB1 shaft. Emma Culligan reports that the first three date to the early to mid-1800s, possibly the late 1700s. The fourth nail dates to the mid to late 1700s.
In the War Room, the team meets by video conference with gemologist Jeffrey Bilgore and John W. Ford Sr., CEO of the American Gem Trade Association, to discuss the glass gemstone found on Lot 5. The experts identify the gem as European, possibly from England, France, Spain, Portugal, or Italy, and date it between 1730 and 1775. When Marty asks about its use, they explain it could have been worn as adornment or sewn onto heavy fabric. They note the size and purity are unusual, roughly equivalent to an eight-carat sapphire or diamond, and not something an average person would have worn. The way the gem is fastened and cut indicates wealth, nobility, or a military decoration. Jack Begley observes that the dates align with the Duc d'Anville theory.
Steve presents his analysis of the swamp features. He maps the survey stakes found this season, then overlays the newly discovered cobble and shows how it aligns with the existing cobblestone path, connects to the Eye of the Swamp and the wooden platform found this year, and projects toward the cobble near the brick vault. Dr. Spooner adds that the features are also related in time, placing them between the late 1600s and mid-1700s. Alex points out that extending the line to the northwest could project it onto Lot 5.
