Thomas and Percy have finished their day's work at the docks and decide to play a game of "hide 'n' peep" until it is time to go home. Cranky wants to join in too, but he cannot as he is much too tall to hide. Percy soon finds a great place to hide - beneath the coal hopper, but the hopper starts moving and he is ordered to move. Next, it is Thomas' turn to hide, but he cannot find a good hiding spot, so he gives up and it is Percy's turn once more. This time, Thomas cannot find Percy at all, so he gladly excepts help from Cranky who immediately spots Percy. Unfortunately, Percy is stuck again so Thomas goes and gets Rocky to lift Percy back up onto the rails. Both engines thank Cranky and promise that, next time, he can play too - although the engines are quite determined that they do not want to play "hide n' peep" for a long time to come!
- Rocky is referred to as a "crane engine", but he is not an engine.