Ep 4. Sin City

In Supernatural season 3 episode 4, titled "Sin City," Dean and Sam take on a case in the city of sin, Las Vegas. The episode opens with a man committing suicide by jumping off a building. The brothers investigate and discover that the man was under the influence of a demon. They soon realized that there is a group of demons causing people to give in to their darkest desires, leading them to sin and ultimately, death.

The episode cuts between Dean and Sam's investigation and the story of a young woman named Casey, who is struggling to overcome her addiction to gambling and alcohol. She meets a man named Father Gil, who helps her get sober and turn her life around. However, it's later revealed that Father Gil is actually possessed by a demon and is the leader of the group causing people to sin.

Dean and Sam race against time to stop the demons and save the people of Las Vegas. Along the way, they team up with an unexpected ally, Bela Talbot, a thief who has a history with the Winchesters. Bela has her own agenda, which clashes with the brothers' mission, leading to some tense moments.

As the episode progresses, the stakes get higher and the danger intensifies. The demons unleash chaos on the city, using their powers to manipulate and control people. Casey gets caught up in their games, and it's up to Dean and Sam to try and save her before it's too late.

The episode features some of the show's most intense fight scenes, as the brothers battle demons and each other in their quest to save lives. It also delves deeper into the mythology of the show, exploring the nature of demons and their motives.

Overall, Supernatural season 3 episode 4 is a thrilling ride that keeps viewers on the edge of their seats. With engaging characters and a strong storyline, it's one of the standout episodes of the season.