Jack Cassidy guest-stars as O'Casey, a shiftless dreamer whose get-rich-quick schemes have brought nothing but grief for his wife (Diane Baker) and daughter Cassie (Lisa Gerritsen). When O'Casey hatches a duplicitious scheme to sell and reclaim a race horse, Hoss Cartwright takes it upon himself to reform the ne'er-do-well, and to simulatenously restore Cassie's faith in her dad. Portions of David Rose's background music were later adapted for the series' classic 1972 episode "Forever." Written by old Hollywood and network-radio hand True Boardman, "Cassie" was originally shown on October 24, 1971.