Mary Watson’s tale begins in Brisbane in the 1870s, when, aged nineteen, she flees an abusive and drunkard father and finds employment as a pianist in a whorehouse in Cooktown run by a Frenchman, Charley Boule. Determined to improve her prospects, she secretly signs on to more lucrative employment: spying on smuggling rackets. It is not clear what is being smuggled – it might be guns – but within a year Mary has dug herself deeper into espionage. She marries a bêche-de-mer fisherman, and goes to live with him on isolated Lizard Island, off the Queensland coast. There, she continues her dangerous and covert work, signalling messages to ships in passage along the coast.