Chuggington (2008)

Season 3: Episode 12

Skylar is doing some rescue training with the trainees, if they pass they get some high visibility stripes and a place in Skylar's Squad! Olwin helps Sylar by taking Hoot and Toot off for some extra training. They play a game of hidey chuggers, Hoot and Toot try to find Olwin. They think they hear her down a tunnel in the mountain but they have been following their echo.