Former highwayman Captain Billy Rhys travels incognito from Scotland to Pembrokeshire to investigate the death of a friend and comrade-in-arms and to uncover a plot to place James Stewart on the throne, which questions may be connected, especiallly as the Jacobite spy Charles Butler has been seen in the area. Billy uses the guise of being a groom to a stallion visiting many of the castles and manorhouses in the area. He is both helped and hindered by his wife and his sister and by Helen, the beautiful hotheaded widow of his deceased friend, all of whom had once been involved in his criminal activities. When things go awry and the authorities are slow to act, it is up to the women to save him and the kingdom. The highwaypersons must ride again. This is a murder mystery, an exciting adventure and a bawdy romp all against the background of a little-known historical event.