Avsnitt 4

Neb is rescued when a vine is lowered to him, although when Captain Harding and Herbert arrive, both deny being responsible. For Harding, it is another sign that they are not alone on the island. When the sea chest is brought back to Granite House it is found to contain a wealth of ship building tools and other supplies. Eager to get to work on a new boat, the group set out to look for materials and come across the remains of their balloon . Transporting it back down river, their raft overturns in the rapids and washes Pencroft, Gideon and Neb towards a raging waterfall. When all hands are safely rescued, the castaways return home to discover their home has been visited while they were away. Herbert and his father take their new boat out on its maiden voyage but encounter an unknown force at sea that pulls Herbert overboard…