Complex sentence: Thomas marries a wealthy young woman, Lucille kills the patriach of her family, the wife goes to Cumbria and the siblings poison her and use the bride's inheritance to fund Thomas's inventive efforts.
Split into simpler sentences: Thomas marries a wealthy young woman, Lucille kills the patriach of her family, the wife goes to Cumbria and the siblings kill her. They use the bride's inheritance to fund Thomas's inventive efforts.