Acclaimed beauty and singer Harriet Gow has earned a position envied by many women of the Restoration period: she is the King's favourite mistress. After seeing her perform, Christopher Redmayne is also captivated and the impression Harriet made is still lingering in his mind when he is summoned urgently by Charles II.
Harriet has been kidnapped and Redmayne, with the help of his friend Jonathan Bale - a Puritan constable - is engaged to resolve this delicate affair. The facade of elegance and gentility soon begins to crumble in the face of their investigations. Harriet is, indeed, an amorous nightingale; the fabric of her life entangled in jealousy, avarice and lust. Just as Redmayne and Bale start to question whether she is really the victim or the guilty party a brutal murder provides the answer...