Old sea stories - especially about ghosts - are favourites amongst the tugs of Bigg City Harbour. No one will admit to taking them too seriously; so when Big Mac rushes back to the Star Pier one foggy night the other tugs laugh when he tells them he actually saw the "Ghost Fleet" looking for lost tows. However, mysterious things happen the very next night that make the Star Tugs uncertain as to whether the Ghost story is true or not.