An unidentified metal object is found on Kiska Island, while a centuries-old gold mining mystery is investigated. In Siberia, a network of ice tunnels is explored, while fossils unearthed in the Canadian Arctic lead to the discovery of a new species.

Mountain climbers in California find the body of a US Army soldier, strange bundles of canvas and wood are discovered on an Alaskan mountain and volcanic glass is found in an unexpected place. A vital Second World War weather station is uncovered.