This week’s episode, "The Chitters," starts off in Colorado, 1989. Two brothers, out for a morning fish, are in a hurry to get out of the town they live in. When the younger brother takes a moment to heed nature’s call, the older brother is dragged away by a creature. The younger brother runs away in terror.
Skip to 27 years later, and Dean and Sam are reading about a case of a large number of missing townsfolk in the same Colorado town. They discover that, every 27 years, a group of people go missing. Sam and Dean make their way into town. A witness whose friend was taken describes a creature that was naked and pale, with flashing green eyes and no hair. It was shaped like a man or a woman (it was junkless) and made a buzzing sound.
A woman in town explains that her grandmother used to say, once a generation, people in town would catch "the Chitters.” People would have orgies and attack others, and their eyes would turn green with lust, and they’d literally buzz with desire.
When a young couple comes across a group of “Chitters” in an alley, the boy gets attacked and the girls runs. She explains what happened to the sheriff, Sam, and Dean and how she recognized the “Chitters” in the alley -- all of them are people from around town. The sheriff confirms that the people she saw as “Chitters” are the people who have been reported missing.
Dean heads off to investigate the forest while Sam goes to check out the alley. While in the forest, Dean is attacked by one the Chitters but is saved just in time by two new hunters. The two men are a couple, one of whom, Jesse, is the younger brother from the previous attacks in town. They have returned to end the Chitters once and for all.
They explain that these are actually Cicada-like creatures who come from underground to mate once every 27 years. They have to use human vessels to mate, which is why the Chitters are in the bodies of the townspeople.
Together, they find the nest and burn it to the ground and kill of the last of the creatures, so there will be no return in 27 years -- but not before they find the body of Jesse’s brother. They are able to give him a proper goodbye. Sam and Dean decide that maybe these hunters are the help they need to find Cas and defeat Amara, but, before they can ask, the couple reveal that they were hanging up their hats as hunters and heading to their ranch in New Mexico to raise horses. Sam and Dean don’t have the heart to keep them from crossing the finish line, something most hunters never get to do.
It’s not often we see a happy ending on Supernatural, so, as much as I would have liked to have seen these new hunters stick around, my hat's off to them.