The mighty water-wheel at Laxey mines in the Isle of Man has been set in motion. In its great shadow, Sarah and Patrick have fallen in love. It is a love that must be kept secret, for Patrick is Irish. Sarah's mother -- Judith -- has lost her mind and blames an Irishman for her husband being imprisoned 'across the water' in Liverpool, where she can never visit him.
The two young lovers desperately desire to wed and be together, but Judith's increasing madness, which began when she lost some of her childer to a savage disease and deepened on her husband's incarceration, proved too strong a pull.
Sarah's deep loyalty to her mother also stands between the lovers, indeed life itself thwarts their every effort to find a way toward their happiness.
Patrick's friend -- Robert -- is going to Australia to make his fortune mining for gold and has asked Patrick to accompany him. With no other option and seemingly with the cards stacked against them, Patrick and Sarah are both heartbroken.
Knowing that her mother will never recover from her illness and will always need her support, Sarah tells Patrick he must go with Robert to make a life for himself without her, and to forget her, and the love they share.