Steve Guptill, Terry Matheson, Charles Barkhouse, and Craig Tester are in the Money Pit where the drill rig has moved to Borehole D1.5, one of twenty boreholes the team has laid out in an area where they have discovered possible tunnels dating to as early as the 15th century, metal objects, and water samples containing gold and silver. A core from 84 feet contains wood at its end, though the structure appears to have been only grazed. The wood could be connected to the tunnel found 2.5 feet away in Borehole D2 at approximately the same depth, where wood dated from 1488 to 1650 was recovered at 88 to 91 feet. The next core from 88.5 feet again shows wood at the bottom, and both Steve and Terry believe the drill is scraping the side of something. Alex Lagina calls Rick and Marty to the Money Pit after a round wood chip and what appears to be a dowel fragment are found at 92 to 93 feet, along with a beam about six inches thick. Alex points out that wood has now been hit across a 12-by-18-foot rectangle, potentially outlining a chamber. Charles Barkhouse suggests the construction may have used dowels rather than spikes, and Rick instructs the team to take the borehole to approximately 150 feet.
On Lot 4, Steve, Laird Niven, Gary Drayton, Jack Begley, and Doug Crowell arrive to investigate eleven metal targets identified in the magnetometer report the team received the previous week. Gary soon recovers a small curved piece of copper alloy that is too thin to be part of a cooking pot according to Laird. Returning to continue the search for the hatch, Jack and Gary unearth an old buckle with a leather strap that Gary says could be from a belt with a pouch for carrying musket balls, flint, or coins. They then recover a button that will need to be cleaned before any design can be identified. At the archaeology trailer, Kelly Bourassa runs an XRF test on the button before cleaning, and the results show copper, tin, zinc, lead, bismuth, silver, and gold. Kelly explains the gold could come from gold plating, gold in the surrounding soil, or the composition of the metal itself.
In the swamp, Alex, Laird, and archaeologists Helen, Liz, and Miriam continue work on the stone road in the southeast corner after Laird obtains permission to excavate the far-west section. Helen explains that a new unit was opened to understand why the road seemed to disappear, and the team found a level layer of stone with a large piece of wood on its edge that lines up with the road heading north. Laird then reveals they uncovered a substantial root growing beneath the stone road, which will be sent for carbon-14 testing. In the War Room, Marty announces a decision to scale back archaeological methods for the time being. Laird will remain on the island in an advisory role, but Miriam, Liz, and Helen will depart at the end of the week. Before they leave, the team gathers at the swamp for a final meeting where Helen reports they were able to determine which direction the road is heading. Rick credits the archaeological process for many of the discoveries made on the island, and both Alex and Marty thank the archaeologists for their work.
In the final War Room session, Craig presents the carbon dating results for the root found beneath the stone road. Laird explains the team had planned to bisect the road to obtain samples for carbon-14 or dendrochronology dating. Craig tells the group that both the outer and inner portions of the root returned the same time period: 1474 to 1638. Steve notes that this aligns with the wood from D2 and CD2.5, which dated 1488 to 1650. Because the root was already in place when the road was built on top of it, the construction must have occurred during or after this window. Dr. Ian Spooner adds that these dates are also consistent with the stakes found along the cobble path.
