A week after Amara took Cas/Lucifer, the Winchesters are getting nowhere in tracking her down and so decide to keep busy by investigating a case.
They head to a Colorado mining town where every 27 years there's a spate of disappearances, and the most recent have thrown up reports of "monster sightings".
While there, Sam and Dean encounter a pair of hunters - Jessy (Lee Rumohr) and Cesar (Hugo Ateo) - with a personal investment in tracking down the creatures responsible.
The Chitters has some nice subtext about brotherhood and the fleeting satisfaction of revenge, but ultimately it's a very by-the-book, traditional, monster-of-the-week story.
I was hoping for a bit more lore about antagonists of the tale, but Nancy Won's script was more interested in the human story.
This is no bad thing, of course, but it just felt like a slight waste to introduce the Winchesters to a creature they had never encountered before, and could learn nothing about, and then for that not to be the focus of the story.
What I didn't understand is that the information Jessy and Cesar accessed on the story's creatures - and shared with Sam and Dean - didn't appear to be particularly obscure (by Supernatural standards), so I didn't see why the Winchesters came up blank in their research.
Battlestar Galactica's Dualla aka Kandyse McClure pops up as the town's superfluous sheriff but then disappears from the overstuffed story as well, without any real arc to her character.
I feel as though The Chitters could have benefited from some trimming of the fat and refocusing of its core narrative to have made it either about the Winchesters meeting an entirely new species of monster or about them helping fellow hunters with a deep, personal connection to a case.