The family go for a weekend break in a horse-drawn caravan. Sheltie goes too and soon makes friends with Toby who pulls the caravan. Toby is lazy and Sheltie has to keep him going. The highlight of the holiday is a trip to Bird Island across a wide stretch of sand. Toby wanders off and they are in danger of being cut off by the tide. As the caravan wheels get stuck in the sand, Toby gives up and, even with Sheltie's encouragement, won't pull any more. Finally, Emma and Sheltie ride across the sands for help and save everyone from the incoming tide.