The year is 1851 and Conor Fitzgerald, a former Midshipman in the Royal Navy having passed his Lieutenant's Examination fins he cannot get a Navy commission. He obtains a position as second mate on a merchant sailing ship that is heading for Callao, Peru, with a party of 180 Irish immigrants. To get to Callao the ship Louisa has to sail around Cape Horn in winter when it runs into more than just bad weather.
They arrive in Callao where the immigrants plans to set up a farming community are set back when they find that disease is rampant and they lose many in their number.Conor decides to stay in Callao where he goes to work for a Scottish ship chandler.
When the famous Italian freedom fighter Giuseppe Garibaldi arrives in Peru in October 1851 he and Conor become friends but Garibaldi has enemies from his previous military encounters and none greater than the French. The French colony in Lima tries to humiliate him and when that doesn't work they set out to kill him. Conor finds himself drawn into these events and is forced to fight for his own life while trying to work out his future and his marriage prospects.