As often with Verne, English translations have appeared under different names; another edition has the overall title Captain Grant's Children and has two volumes subtitled The Mysterious Document and Among the Cannibals.

An unexpected passenger in the form of French geographer Jacques Paganel (he missed his steamer to India by accidentally boarding the Duncan) joins the search.

However, Ayrton is a traitor, who was not present during the loss of the Britannia, but was abandoned in Australia after a failed attempt to seize control of the ship to practice piracy.

However the Glenarvans, the Grant children, Paganel and some sailors are left in Australia, and mistakenly believing that the Duncan is lost, they sail to Auckland, New Zealand, from where they want to come back to Europe.

Ayrton, made a prisoner, offers to trade his knowledge of Captain Grant in exchange for being abandoned on a desert island instead of being surrendered to the British authorities.