After reading from a spell book from the 1600s, Lana along with Lois and Chloe are possessed by vengeful witches who were burned at the stake; Clark is unable to stop the witches from wreaking havoc on the town.
When Lex is accused of killing a young woman, Clark tries to establish his innocence by seeking Lionel's help.
Sam and Dean tackle a case where people vanish into thin air, leaving only their clothes behind; Dean becomes a victim.
The agents investigate deaths and disappearances near a lake where small-town residents revive stories about a legendary killer sea-serpent.
Fifteen people along the Eastern seaboard suffer retrograde amnesia after listening to their shortwave radios on the same frequency; the anticipation of Olivia's return escalates.