An aristocratic woman, Lady Isabel, leaves her husband and children when she suspects him of adultery, a notion which had been suggested to her by the scheming and murderous Captain Levison. Life on the continent with Levison does not work out as she had envisaged so, eight years later, she returns to England and finds her husband has remarried. She cannot bear to be away from her family and so dons a disguise, gaining employment with them as a governess. When her young son, Willie, dies she is unable to comfort him as she would like, and she too dies.
