Watch Online Free on Watchseries. Devious Diesel returns to the Island of Sodor, but the future is chasing him. British Rail, facing record-low passenger numbers, is supercharging its main lines with electrification. Meanwhile, small, unprofitable branch lines are being axed - along with their rolling stock. Across the UK, early diesel engines, once revolutionary and new, suddenly face the same fate as the steam engines they replaced.