John Pennington and his crew want to mine the Ponderosa land by hydraulic means. Ben is totally against this method and evicts them in short order. Hoss is given the task of telling Pennington's men to leave, but soon has a moral dilemma on his hands when he meets Pennington's beautiful sister, Emily. He soon discovers a heartbreaking secret...she's terminally ill; but their relationship soon leads to plenty of trouble for the Cartwrights.
Guest Star: Diane Grey (Wyoming), Byron Foulger (Justin Flannery), Robert Knapp (John Pennington), John Larch (Blake McCall), Inger Stevens (Emily Pennington), George J. Lewis (Jose Moreno), Martin Mason (First Miner)