Ep 3. Croatoan

In the 13th season of Supernatural, episode 3 is titled "Croatoan" and opens with Dean and Sam arriving in Rivergrove, Oregon. They are investigating a series of disappearances within the community which have left the locals extremely on edge.

The brothers quickly realize that the disappearances are likely linked to the town's dark past. Rivergrove was founded by a man named Cyrus Styne, who turned it into a breeding ground for a cult of devil-worshippers.

In fact, the cult's influence was so strong that they managed to summon a demon, causing the entire town to be consumed by a malevolent force known as 'Croatoan'. Once infected, the people started to suffer from a range of demonic symptoms; they became violent, irrational and were overcome with an all-consuming bloodlust.

As the brothers investigate further, they discover that the current crop of disappearances look all too familiar. The people who have gone missing in Rivergrove have all been infected by the same demon as before, and soon enough, they find themselves caught up in the darkness of the town's sinister history.

With the help of local sheriff Donna Hanscum, Dean and Sam begin to piece together the truth behind the rash of recent disappearances. They learn that the demon can only be defeated if they are able to re-create the same ritual that initially destroyed it.

As they delve deeper into Rivergrove's past, they realize that the solution may be even more complicated than they first thought. Not only must they find a way to recreate Styne's ritual, but they must confront the fact that the cult is still active, and may still be trying to summon the demon.

The episode culminates in an intense showdown between the brothers and the remaining Cult members, as they race against time to destroy the demon before it spreads beyond the confines of Rivergrove.

Overall, 'Croatoan' is a gripping and action-packed episode that continues to explore the rich mythology of the Supernatural universe. With its dark and ominous setting, intense twists and turns, and satisfying resolution, it's a must-watch for fans of the show.