Still serving aboard the HMS Indefatigable, Horatio Hornblower has been promoted to acting Lieutenant. Neutral Spain has concluded a peace treaty with France and the British now have another enemy to face. They soon come across a sunken British supply ship and rescue its Captain, 'Dreadnought' Foster, a man with a reputation for bravery that some consider borders on foolishness. Hornblower is also pleased to learn that Captain Pellew has scheduled him for the next round of Lieutenants exams. Tempers are short with the crew after they are put on half rations due to the lack of supplies. After acquiring more supplies, Hornblower finds himself in charge of a supply ship when it is feared that plague may also be aboard. He soon makes it to Gibraltar, but when the enemy send a fire ship into the harbor, he must act quickly to avert disaster.