James is 17 and is pretty sure he is a psychopath. Alyssa, also 17, is the cool and moody new girl at school. The pair make a connection and she persuades him to embark on a darkly comedic road trip in search of her real father.

Koko, Brewster and Wilson are three young, adventurous trainee "chuggers", learning about working on the railway in the town of Chuggington, with the help of the railway controller, Vee, the older engines, and their human friends.