Jack Carstares, the disgraced Earl of Wyncham, left England seven long years ago, sacrificing his honour for that of his brother when he was accused of cheating at cards. Now he is back, roaming his beloved South Country in the disguise of a highwayman. Not long after his return, he encounters his old adversary, the libertine Duke of Andover, just in time to dispute at the point of his sword the attempted abduction of a society beauty. But foiled once, the 'Black Moth' has no intention of failing again...