Smokey and Steamer are first seen fixing the locomotive's headlamp while Hero Girl is put in charge of driving the train. Smokey suddenly catches sight of something ahead on the tracks and Steamer calls out to Hero Girl to stop the train. After she and Hero Boy, who is with her in the cab, debate on which lever is the brake, they manage to stop the train right before crashing into a herd of caribou. The Conductor, Hero Boy and Hero Girl arrive at the front of the locomotive to try to help. Hero Boy slips, but breaks his fall by grabbing onto Smokey's long beard, causing him to scream in pain. Everyone soon realize that the caribou can understand Smokey's screaming, so the Conductor continues to pull Smokey's beard to try to communicate with them and get them to clear the tracks. The caribou eventually do so and Smokey and Steamer get back to the engine room to get the train moving again.
The train is on its way again, but Steamer finds that the throttle has jammed and tries to fix it. He was so busy trying to fix it that he did not listen to Hero Girl calling out to slow down. The throttle's cotter pin eventually falls off and through the grate, but comes out again while the train goes down Glacier Gulch. Smokey and Steamer try to catch it and Steamer does so successfully with his mouth, but swallows it by accident.
When the train ends up on the Ice Lake, Smokey tries to retrieve the pin by hitting Steamer's back with a shovel, which works too well as the pin flies out of the engine room and pierces the ice. With no other option, Smokey decides to use the pin from his hair to fix the throttle and Steamer is able to stop the train. The Conductor scolds them for what had happened, but after Hero Boy catches sight of the ice crack getting bigger, he orders them to get the train off the lake. They soon find the tracks on the other side of the lake and with the Conductor navigating, Smokey and Steamer get the train off the lake and back on the tracks.
Smokey and Steamer are two of many characters from the film to have not appeared in the book.
The pair's names are only revealed in the credits. Had the deleted scene, "It Takes Two" not been cut, their names, as well as the fact that they are twin brothers would have been revealed in the actual film
This was Michael Jeter's final acting role before his death.