It is Winter 1720. Kate Francis and her father, Joe, are travelling by wagon from Yorkshire to London. This is Joe's last journey as he is selling his business to take over the running of a tavern his deceased brother owned in Covent Garden. Twenty miles from London their wagon is waylaid in a snowstorm by the notorious highwayman, Jack Lance and his gang. Joe is killed and his money is stolen but Kate survives and struggles on until she reaches the estate owned by Harry Collins, the Earl of Brideswell.
The finances of the Brideswell estate are in parlous state and Harry, when Kate arrives, is in deep discussion with his younger brother, Algernon, about finding a solution. Algernon advocates investing in South Sea stock but Harry is cautious. Kate's arrival presents a diversion but none of them realise just how complicated the outcome will be...