This is book 5 of the "Aubrey-Maturin" series.

This note contains spoilers for the book.

Now commanding the "horrible old Leopard", fixed up by the dockyard, Aubrey is off to settle the problem "Breadfruit Bligh" is causing in Australia, and incidentally take some convicts there, including a gentlewoman. Who happens to be a friend of Diana's and an American secret agent. Aubrey hates transporting prisoners (it's pretty clear he considers most of the sentences unjust), but Maturin convinces him to do it. They also have a stowary, Mrs. Wogan's lover, Michael Herapath.

Aubrey has a set of officers he mostly doesn't like, including Grant, who had an independent exploring command and knows those waters, but knows nothing of fighting a ship. It gets worse when "jail fever" carries off a lot of the convicts, the men, and nearly Tom Pullings, who they have to put ashore in South America to recover.

Then they have the huge battle with the Dutch 74, the Waakzaamheid, who pursues them relentlessly, in weather conditions where a battle will result in the total destruction of one ship or the other. Aubrey just barely wins, and is devestated by the thought of 500 or so men being killed that quickly. Also he's hit by a splinter and then a recoiling gun.

And then they hit an iceberg, and after failing to find and patch the leak, with the ship nearly foundering, most of the men head off in the boats, lead by Lt. Grant.

Steven has set a very pretty trap for American intelligence, which will tell him whether they're cooperating with the French, and confuse both. And things keep happening to prevent his sending his report, and Mrs. Wogan from sending the information. They skip the cape, heading straight to Australia, and then hit the iceberg.

They do eventually reach the island of the title, and are found there by an American whaler, which can loan them use of its forge, and is just barely willing to do so—America and England are on the brink of war, and England has been rather provoking, including The Leopard firing into the Chesapeake some time ago. Jack and Stephen both have to display their diplomatic skills to get that to work out.

The book ends when the American leaves, taking Mrs. Wogan and Herapath and Stephen's carefully poisoned documents with it.