Lieutenant Cornelius Vanslyperken is the greedy and treacherous commander of a small vessel that hunts for smugglers in the English channel. Snarleyvow is his "indestructible" dog. Set in 1699 and framed around the Jacobite (supporters of the overthrown king, James II) conspiracies of the time, this is the first of three works in which Marryat builds his story around historical events, rather than those of his own time.