Mary Reilly lives in the house of Dr. Henry Jekyll. She serves her master as a loyal housemaid, sensitive to his weaknesses, attuned to his needs. An innocent girl, Mary's placid demeanor belies a core of steel that has enabled her to overcome a past scarred by violence and pain. In the service of Dr. Jekyll, she has found a safe haven at last. Mary's trust is a blessing to the doctor as he embarks on a new experiment, one which requires sympathy and understanding, discretion and silence. She is about to meet his elusive, shadowy assistant Mr. Hyde, and through him she will come face to face with the darkest, most private aspects of herself. Devoted to the brilliant, reserved Dr. Jekyll, Mary finds herself drawn to the seductive charms of Mr. Hyde. Together they share a terrible secret which casts a shadow of fear and danger on the Jekyll household. As Hyde grows stronger, the gentle doctor weakens, and only Mary can unravel the awfuly, unholy truth.