Complex sentence: A mine is dug, and much gold is extracted, but greed soon sets in and Dobbs (Humphrey Bogart) begins to lose both his trust and his mind, lusting to possess the entire treasure.
Split into simpler sentences: A mine is dug, and much gold is extracted. Greed soon sets in and Dobbs (Humphrey Bogart) begins to lose both his trust and his sanity, lusting to possess the entire treasure.