When Gordon's coupler breaks, Thomas promises to deliver his cars to Whiff's Recycling Plant, but will Thomas be able to fulfill his promise or will his contest with Diesel distract him?
Thomas and his friends are asked to deliver pieces of a space rocket to Brendam Docks. Thomas is disappointed when the only piece left for him to take is a little battery, so he tries to help his friends with their larger parts.
When Percy has to deliver a new light bulb to the lighthouse at night, Thomas suggests playing secret agents along the way to help Percy forget about his fear of the dark.
Thomas forms a Big Adventure Club with Percy and Carly and they all think Sandy is too little to join them in the search for the legendary Crystal Locomotive.
Thomas, Percy and Nia have to make a delivery to Wayland on the Mainland. As the the trip will take a couple of days, they have to camp out in the woods overnight, but Percy is anxious.