In 1947, a shipping mishap sent an entire train assembly to the bottom of Slocan Lake in British Columbia, a lake nearly 1000 feet deep. Seventy-five years later, a diver and his team set out to find and raise the steam locomotive, working with a 99-year-old brakeman who was on the train the day it went down. The film follows the expedition through the technical demands of deep freshwater diving, the cold, the pressure, and the limited visibility that make Slocan Lake one of the harder recovery sites in Canada. Interviews with the diving team and archival material trace how the wreck happened and what the locomotive meant to the rail line running through the region. As the search continues, the crew keeps running into the small mountain communities that grew up around this stretch of track, and the film widens to take in what the railway's history meant to the people who still live there. It closes as much on the town as on the train.