In the 17th volume in the popular high-seas nautical adventure series, it is 1807 and Captain Sir Thomas Kydd's famous sea action aboard Tyger has snatched his reputation from ignominy. He is the hero of the hour. But although the British Navy remains imperious, a succession of battles has seen Napoleon victorious on mainland Europe. His enemies have sued for peace and the emperor's Continental System, establishing a European blockade, will leave Britain cut off from her economic lifeblood.

One small link in this ring of steel is still free of French control: the neutral state of Denmark, which controls the straits through which the entire Baltic trade passes. In an attempt to prevent the French from taking control of Denmark's navy, Kydd's great friend Nicholas Renzi – now the Lord Farndon – is sent on a desperate diplomatic mission to persuade the Danes to give up their fleet to Britain. But the Danes are caught between two implacable forces and will not yield, opting instead for the inferno of battle.