It's Halloween in Purgatory, and Jeremy tasks Wynonna and Waverly with neutralizing Rotten Jack with the help of the extractor.
The sisters go to Casey to get the extractor, but the half-demon takes them across the Ghost River Triangle into the mind-altering fog to get out of helping.
As a result, Wynonna and Waverly forget their memories and head back to the Homestead to find out who they are.
Wynonna believes she's a bartender at Shorty's named Waverly, and Waverly believes she's a cop named Wynonna.
They then head to Shorty's and run into Doc. Demons then appear, and the sisters hide in the dumpster.
One of the demons tells Amon, who's hosting a deadpool for Rotten Jack's victims, and he decides to auction off Wynonna and Waverly to the highest demon bidder.
Jeremy reaches out to Doc for help, and Doc convinces Casey to do his job.
At the Glory Hole, Jeremy reverses the mind-altering fog, and Wynonna, with Casey's help, is able to stop Rotten Jack.
Jeremy then reveals Robin was out in the mind-altering fog for weeks and clawed his own face off.
Jeremy has been trying to reverse the memory loss but hasn't had much luck.
At the end of the episode, Doc leaves Amon to be killed by demons.