Supernatural - Season 11 Episode 20 -
Don’t Call Me Shurley
Amara unleashes a dark fog on a small town, which causes everyone to go mad. Sam and Dean realize this is a stronger version of the original black vein virus Amara previously unleashed. They team up with the sheriff to protect the town but the old remedy no longer works. Meanwhile, Chuck returns with an interesting proposal to stop Amara and save Lucifer and take Lucifer out of Castiel.