On this episode of Supernatural…
Residents go missing every 27 years in a town.
Sam and Dean investigate and learn about “the chitters,” where people start shaking and having orgy-like behaviors.
Dean runs into a couple hunters, Jessie and Cesar, who say it is a cicada-spirit called the bisaan.
The four find the lair.
Jessie and Cesar agree to stop hunting after getting their revenge.