It is two years since Thomas Paine Kydd was spirited away in the night to serve his country aboard the old line-of-battle ship Duke William. Now, together with his high-born friend Nicholas Renzi and other members of the ill-fated Artemis, Tom is a shipwrecked sailor back in the land of his birth. They find themselves waiting to be summoned as court martial witnesses, and in a political act to shield an officer's reputation, they are shipped out in haste to the Caribbean - where sugar is king and yellow jack a fearsome peril.

A spell ashore at the dockyard in Antigua shows Kydd another side of the Royal Navy, the complexities of maintaining Britain's fighting ships around the world. There he also has to deal with a number of personal challenges and in so doing earns the ire of the feared master shipwright. Summarily dismissed from the dockyard, Kydd faces an unknown future.

Renzi contrives to reunite the old crew of Artemis in Seaflower, a graceful and trim little topsail cutter, that Kydd fell in love with the first time he saw her. At first the plucky craft brings them luck and fortune but she is eventually overwhelmed by the raw forces of the sea - and Kydd finds his seamanship, tenacity and courage put to the ultimate test.