Dora the Explorer Season 1 Episode 3 Choo Choo Episode Title:Choo Choo.Episode Description:Dora and Boots visit a train station to see the trains (green, red, and blue) and encourage them to blow their whistles, discovering that the smaller blue train (Azul) doesn't have one. Upon learning that the first prize in the big train race (run by Val the Octopus) to the big yellow station is a big whistle, they assist Azul competing in the race. Following maps directions, they travel over a mountain (assisting Azul with the mountain's steep incline with encouragement cheers) and through a tunnel (assisting Azul with a flash light from Backpack, thus helping them see and almost avoid colliding with an on-coming grey train). The other two trains (green and red) tire from initially going to fast, allowing Azul to win the race. Swiper continually hampers their efforts by initially successfully stealing, and then discarding, a section of the blue line's train tracks (repaired by Dora and Boots after recovering the missing track pieces) and then unsuccessfully attempting to steal the race's whistle prize.