It is the eve of the French Revolution and England awaits with trepidation the news from the Continent that will propel her into war again after six years of peace. But Lieutenant James Hayter's orders from the Admiralty do not at first involve the sea. He must go inland to seek out his friend Captain William Rennie, who has disappeared into the wilds of Dartmoor.
When he finds Rennie alone and broken down in an isolated farmhouse, Hayter fears the Captain will be unable to make the journey to London. Hayter has his own hopes of a command, but these are cruelly dashed when they reach the capital, where they find the sinister spymaster, Sir Robert Greer is once more behind their deployment. They are to sail in HMS Expedient to the Mediterranean, to assist Britain's ally Rashid Bey of Rabhet, with Hayter yet again Rennie's second in command.
So, unprepared for what they will find on the dangerous Barbary Coast, Expedient and the ten gun cutter Curlew sail into treacherous waters. The odds are daunting. They must make a show of defiance against the mighty corsair fleet of Rabhet's enemy the Dey of Tunis. Murky politics, threatened mutiny, desperate sea actions and imprisonment follow on the sweltering North African Coast, where the rules of European warfare no longer apply and the victor will take everything.