Thailand's State Railway becomes the case study for this episode of the trains series, focused on the line built during World War II and known ever since as the Death Railway. Host Teddy Wilson rides the route through the tunnels and river crossings near the Kwai, tracing tracks laid under forced labor by prisoners of war and conscripted workers under brutal wartime conditions. Interviews and archival material fill in how the railway was built and at what human cost, while present-day footage follows the crews and engineers who keep the aging line running through jungle terrain, old bridges, and tight mountain passages. The episode mixes operational detail, how the trains handle the grades, the river crossings, the maintenance demands of infrastructure decades past its intended lifespan, with the history that makes the line notorious. It aired first in Canada in 2019 as part of a series profiling railways around the world under extreme physical and historical conditions, and this entry treats Thailand's landscape and its wartime past as inseparable from the engineering story.