All over the Island of Sodor, there are many things that can slow down the Really Useful Engines. A cow on the line, a fallen mail bag, a broken shipping crate, even those Troublesome Trucks, all of which make wonderful stickers. Little train lovers can strategically place the stickers to slow things down, and then move them to keep things running right on time. And the reusable stickers can be used over and over again.