The movie is a flashback,the narrator tells a story of him when he was a boy .On Christmas Eve,the boy was awakened by some sudden noise and shake,he saw a train outside his window–The Polar Express. The conductor lets him aboard and he met the children on the train,including a girl and a Know-it -all boy. Then they went to pick up a lonely boy Billy, but Billy didn’t get on the train. The boy pulled the emergency brakes for Billy. At first he didn’t want to get on,but changed his mind at last. On the way to the North Pole,the boy mets the Hobo and the Pastry Chefs, developed friendship with the girl and Billy. At the North Pole, the children met Santa and saw the celebration of the band of the elf. A bell breaks loose from a harness and roll down to the boy’s feet, at first he heards nothing, but when he believes  he heards a sound.The kids head home, on the train the children asks the boy to show the bell, but he found he pocket is broken and he had lost it.The next day,the boy’s sister Sarah woke up in excitement, she opens up her gifts under the Christmas tree. There were only a small box left, and it’s for the boy. He opens it up,it’s the bell that he lost,and there is also a message from Santa. He rings the bell and heard the sweet sound,Sarah heard it,too.But when they show the bell to their parents, neither of them heard the sound.At one time,most of the boy’s friend could heard the bell.But after years passed,it felt silent for all of them. Even Sarah found one Christmas she no longer could heard the sound.But to the boy,he always could…

Picked from Wikipedia: In the movie,Tom Hanks played as many characters, including the boy(motion-capture only),the boy’s father,the conductor,the Hobo,Santa Claus and the narrator.Nona Gaye played as the girl. Eddie Deezen as the Know-it -all boy. Peter Scolari as the lonely boy Billy.(They are also other people doing the characters’ additional mention-capture and their  voice)

The conductor punched the word ”BELIEVE’ for the boy on his ticket, ‘LEAD’ for the girl.There are many words on Billy’s ticket, on one side it’s ‘Depend on’, but when he flipped it it turns to ‘Rely on’ and ‘Count on’.In the end of the movie,the boy tells the truth of the bell:’Though I’ve grown old… The bell still rings for me. As it does for all who truly…believe.’ The first time he heard the bell is when he believes,and he could still heard the sound is also because he truly believes.