Demure young beauty Lady Imilda Harsbourne's stepmother, the Countess of Harsbourne, is determined to have Imilda married off to an eligible and 'important' bachelor as soon as possible. But after enduring several Society balls as a debutante, Imilda is thoroughly disillusioned and vows never to marry unless it is for love alone. So she is horrified when her stepmother arranges for her to be wed to the Marquis of Melverley, who, although dashingly handsome, is a notorious 'ladies' man'. Despite her pleas, her father will not help her and she has no choice but to run away. But to where? Then Imilda has a cunning idea. Since his return from the War, the Marquis has never returned to his family seat, Melverley Park, which stands empty apart from a skeleton staff. And so, clutching a forged a letter of introduction from the Marquis, Imilda arrives to take charge of the estate's Herb Garden. While exploring The Park's library, though, she finds to her horror that a gang of cutthroat highwaymen has taken advantage of the Marquis's prolonged absence to use The Park as their lair. When the Marquis arrives out of the blue, running away to hide in plain sight, Imilda keeps out of sight in The Park's secret passages and, overhearing the villains plotting to kill the Marquis, she creeps into his room at night to warn him and help him escape. In the ensuing adventure, in which they enlist the Army to fight off the criminal gang, Imilda realises that she has fallen head over heels in love with the man to whom she is reluctantly engaged.