Claire makes the best of been pressed into service on the Porpoise, taking a firm hand in the treatment of the ill and not letting the doubts of the crew deter her. She befriends the young midshipman appointed as her assistant. Having had all the decks completely cleaned, the sick cleaned and placed in sanitary beds, ordered the distillation of alcohol and the implementation of new hygiene regulations, she starts to gain respect as the number of new cases slow. There are still quite a lot of deaths, and the whole crew is affected by them. While treating the men and making arrangements, she finds out that the Porpoise had boarded a Portuguese ship, prompting her to snoop through the captains log. The ship was not the Bruja, but she discovers something else -- Jamie has been identified and the Captain has plans to use her as bait to arrest him in Jamaica. The goatwoman on the ship, whom Claire has befriended, tries to help her escape when the ship stops at Grand Turk, and when that doesn't work out, Annejka builds a rat out of barrels and convinces Claire to jump overboard with the hope of washing ashore at Coburn.
Jamie does not respond well to Claire being taken by the Porpoise, and even worse when Captain Raines refuses to go after her with all haste. After pulling a weapon on the captain, he ends up in the brig. He tries to convince Fergus to free him and take over the ship, even promising that he will bless the marriage with Marsali if he does. After much deliberation, Fergus refuses. He is more aware that there is no chance that the mutiny will succeed and does not wish to put Marsali or Jamie in danger. Jamie is finally freed when Marsali convinces the captain that he will be of use as they navigate a tricky passage.