Rufus Enterprise chooses Seal Island in King George Sound in the Southern Ocean of Western Australia as the site for his sealing operation. He appoints Tom Elder as his leader with four ex-convicts, Bob Beater, Dick Dental, Harry Heeler, and Sam Scullion to assist him. A group of boys are shanghaied, press-ganged, and purchased to make up the unpaid workforce on Seal Island. The boys are worked hard and treated badly, but some learn invaluable skills under the tutelage of Harry Heeler and Sam Scullion.

A sudden fierce storm sees an East Indiaman ship flounder and founder near Seal Island, but efforts to get a line out to her prove futile. The ship sinks, but there is one survivor, a 'boy in fancy togs' called Adam. Adam is a problem for Rufus Enterprise. He might be worth a ransom or reward, but he also may have seen enough to bring the operation on Seal Island undone. Adam befriends Benjamin and shares with him the dream for a better life. When Rufus Enterprises hears of this so-called dream, he is furious and decides to deal the problem in a wicked way, through a ritual castaway. He retells the terrifying tales and legends of 'Old John' Sullivan to frighten the boys into submission and stamp out all talk of dreams and dreamers.

Benjamin shares the dream with six others who become 'outcasts', when a 'snitch' called Jake, brings them undone. Rufus Enterprise, now infused with a black miasma, is teetering on the edge of madness, and his unstable state explodes into death and destruction. How all this is resolved is the story of the Seal Island band.