Although bookended by a pair of sequences tied to the main season arc, Plush was largely a beautifully self-contained ghost story - the kind that Supernatural does so well.
At first, the episode seemed to be treading similar ground to the Eli Roth-produced Clown, with its central conceit of costumes (or in this case, specifically, masks) that can't be taken off once donned and drive their wearers to commit murderous deeds.
But very quickly, once the Winchesters are called in to investigate by the Fargo-esque Sheriff Donna Hanscum (Briana Buckmaster), last seen in Hibbing 911, it becomes its own entity.
What begins as a morbidly humourous tale takes a turn towards harrowing darkness as the brothers trace the masks to the recent suicide of a children's entertainer.
Season Eleven of Supernatural continues to deliver the goods, building on - and learning from - what has gone before, but continuing to find fresh spins for the material, with no sign of flagging.
As I've said several times before, Supernatural's take on ghost stories are among some of their strongest episodes, hearkening right back to the pilot, and Plush was particularly powerful.