This description by Mathias http://www.onedinlinie.de/

James has beaten Thomas Callon for Braganza's contract in Portugal and sails for Liverpool. The "Charlotte Rhodes" with the cargo of wine is only a short way out when James becomes sick with food poisoning. This is a result of eating tainted meat, which was supplied by brother Robert. James becomes so ill he falls into a coma, and is confined to his bunk. This is a problem, because he is the only one who can take the noon day sightings and understand how to use the information to fix the position of the ship.

Mr. Baines the Mate cannot read and write and has no knowledge of navigation when out of sight of land. Anne knows only some of the basics of navigation which James had shown her earlier on the voyage. She succeeds in plotting an approximate course home.

Baines is convinced that the illness which is now affecting most of the crew is a "contagion of the air". Anne knows this is not true and the real cause is bad food, they do not see eye to eye over this and are at loggerheads. Further bad luck occurs when a crew member is injured.

She takes rigorous measures to prevent new cases of sickness, making them dump most of the supplies overboard, that which remained had to be boiled and made into stews or broth, also all the drinking water must be boiled before use.

The crew is very discontent and think that the cause of all the problems is having a woman on board (which was thought in those days to be bad luck). Then an incident involving two crew members broaching a  cask of wine and drinking some of the contents leads to Anne being insulted and drenched with wine by one of the crew after she accused them of mutiny.

To defuse the situation Baines and Anne make a bargain, she will teach Baines to read and write and not interfere with the running of the ship by undermining his authority.

Anne's navigation is found to be wanting because she has not corrected the course for leeway and the "Charlotte Rhodes" is suddenly in danger of running aground during a storm. Fortunately at this moment of peril James recovers enough to take command and sail the ship safely home.

Meanwhile in Liverpool, Elizabeth who is engaged to Daniel Fogarty is also flirting with Albert Frazer - a sure sign of trouble brewing!

James? How much profit is there?