In the first season episode " Bugs ," Sam and Dean fight to survive a 200-year-old, nature-based curse centered on a cursed Native American site in Oasis Plains, Oklahoma. While the episode is noted for being a weak entry with continuity errors and challenging real-bee filming, it showcases a familial conflict that mirrors the Winchester brother's own relationship issues. The full episode can be explored further on the Supernatural Wiki or through this IMDb overview .