Thomas & Friends S03E15 - Toby's Tightrope

Based on the story of the same name from Tramway Engines.

Mavis has been confined to the quarry and is bitter about not being allowed on Toby's line, so she makes a plan with the Troublesome Trucks to go further down the line. However, things go wrong when Toby arrives instead. Toby is then put in grave danger when the trucks push him onto an unsafe bridge.