Fish is the twenty-fourth episode ever made in Season 4.
Extra vans are needed for "The Flying Kipper" and, to Henry's annoyance, the only ones available are old and unsafe. At Wellsworth, Duck buffers up as a banker to help Henry up Gordon's Hill, but a tail-lamp falls off and Henry slows down while Duck lags behind and eventually crashes into the train. The mess is cleared up in the morning and Duck reflects that Thomas' earlier advice about fish was right.
- Duck's eyes look wonky after Thomas leaves with the post train.