Jack Frost - S6.E16

The weather is getting colder so the Fat Controller asks James and Percy to make extra coal deliveries. Thomas seemingly warns Percy that he should be careful or else scary Jack Frost will get him. James thinks this is a load of nonsense, but Percy believes him. But when night comes and Percy has to make a delivery of coal to Lower Suddery both he and then later James think differently, but not as you would probably expect!