London, 1826: When prominent society couple Mr. and Mrs Benham are found stabbed to death, their maid Frannie Langton is accused of murder.

Frannie and Madame’s illicit relationship develops. Meanwhile, we learn about the horrific experiments conducted at the Paradise plantation.

Frannie and Madame’s secret affair comes under threat as jealousies flare in the Benham house. Madame’s dangerous addiction worsens.

Frannie stands trial. The shocking truths about the Benhams’ murders, Langton’s experiments and Frannie’s past are revealed.