The story starts with a prologue, telling the tale of young British aristocrat, Richard Devine, who is the son of a shipbuilding magnate, Sir Richard Devine. In an incidence of domestic violence, Richard's mother reveals to Sir Richard that his son was fathered by another man, Lord Bellasis. Sir Richard proceeds to threaten the mother's reputation if Richard does not leave and never come back. He leaves him to pack for a while, claiming that he will fetch his lawyer to alter his will so that Richard receives no inheritance. When Richard leaves, he comes across a murder scene: his biological father, Lord Bellasis has been murdered, and Richard witnesses Sir Richard walking away from the scene of the crime. The police come and lock up Richard, who now gives his name as Rufus Dawes (which is used for the remainder of the book), for the murder of Lord Bellasis. Additionally, Sir Richard returns home and dies straight away, possibly of a heart-attack, without altering his will. Rufus Dawes/Richard Devine never finds this out. Rufus is found not guilty of the murder but guilty of the robbery of the corpse and sentenced to transportation to the penal colony of Australia.

In 1827, Dawes is shipped to Van Diemen's Land on the Malabar, which also carries Captain Vickers, who is to become the new commander of the penal settlement at Macquarie Harbour, his wife Julia and child Sylvia, Julia's maid, one Sarah Purfoy and Lieutenant Maurice Frere, Richard Devine's cousin, son of Sir Richard's sister, who would have inherited the fortune in Richard's place. It turns out that Sarah is on the vessel only to free her lover, John Rex. She organises a mutiny with the help of three other men: Gabbett, James "Jemmy" Vetch or "the Crow" and a man nicknamed "the moocher", while John Rex is in hospital with the fever. One night, a burning vessel is sighted and found out to be the Hydaspes; the ship on which Richard Devine is supposed to have sailed. The crew cannot be found. The following day, Dawes overhears the plans of the mutineers, but is taken to the hospital sick with the fever shortly afterwards. He manages to warn Captain Vickers and Doctor Pine about the plans. Sarah gets the Captain drunk and Frere otherwise busy but does not know about Vickers clandestinely doubling the guard. The mutiny is, therefore, unsuccessful, but Jemmy Vetch, who has understood that only Dawes could have betrayed them, gets his revenge by claiming that Dawes was the ring leader of the mutiny. Dawes is found guilty and receives a second life sentence.