In 1802, during the Napoleonic Wars, former British naval officer Jack Vincent operates as a smuggler along the rugged coastline of the West Country. A charismatic and morally complex loner who lives by his wits and his sword, Jack is driven by a Robin Hood-like sense of justice, targeting the corrupt system that taxes ordinary people into poverty while the wealthy flaunt their fortunes. His independent operations bring him into constant conflict with rival criminal gangs, His Majestys customs officers, and even French spies who complicate the already dangerous smuggling trade.

Jack is joined by two key allies. Honesty Evans is a light-fingered petty thief whom Jack rescues from a shipwreck in the opening episode, and he provides both comic relief and resourceful assistance. Sarah Morton, the mistress of Morton Hall, becomes a figure of intrigue and romance, often involving Jack in her personal troubles. Together, the trio navigates a treacherous world where the line between criminal and patriot is frequently blurred.

The primary antagonistic force is the Kemble Gang, led by the sinister brothers Silas and William, who rule their territory through brutal violence and resent Jacks refusal to join or bow to their operation. Throughout thirteen episodes, Jack and Honesty contend with a wide array of threats. In Forced Run, a smuggling run to France is jeopardized by a stowaway. In the two-part story The Respectable Traitor, Sarah begs Jack to clear her grandfathers name after he is falsely accused of being a French spy, a plot orchestrated by the Kembles. Press Gang sees Honesty forced into naval service, requiring a clever rescue. Later episodes involve recovering a sunken cargo of rum in Hogshead, rescuing Sarah from shipwrecked convicts in The Felon, and confronting sailors from Jacks mysterious past who accuse him of treachery in An Eye for an Eye.

The series culminates in a two-part finale, Straw Man. After Jack rescues a revenue officer named Arrow from an attack, the officer is later found murdered with Jacks knife at the scene. Despite his denials, Jack is arrested for the murder, and the dead mans friends arrange for him to be shot while attempting to escape. The story does not conclude there, as six years later, the character returned in a sequel series, Adventurer, which follows Jack aboard a prison ship being transported to a penal colony.