Thomas takes an eager front-loader named Jack to help the Pack clear ground for railway lines at the quarry. Jack looks for his work, and finally finds it, working with a small excavator called Alfie. Then, a dump truck called Max comes along, and causes dust to fly over the machines. Jack tells Max to stop bullying. Max scowls and races away. Later, Jack foolishly tries to take some rocks up a hill. He loses his balance and rolls down the hill. Jack is upset and Miss Jenny is disappointed, but Isobella, Alfie, and Thomas are sympathetic, saying he is still really useful.