The Challenge (1998)

S12E14 Don't Go Back

At the Quarry, Diesel dares Thomas to a backward race around the site, but their antics lead to Mavis, Arry, and Bert derailing. Meanwhile, Henry arrives to pick up his trucks, which Thomas and Diesel were meant to load with stone from the Quarry. After completing their task, the two engines decide to have one final race, this time moving forward, and they cross the finish line together.