On this week's Supernatural...
Dean struggles with the after effects of the mark of Cain.
Sam hears about a case about straight-laced people turning into murderers. When Dean doesn't want to go on the hunt, Sam goes it alone.
While investigating, Sam meets an elderly woman named Julia who tells him the Men of Letters came to her town in 1958. She tells Sam about Henry Winchester and his companion named Josie who was taken over by Abaddon.
Sam discovers Abaddon is stealing souls and attempting to build a demon army loyal to her.
Crowley tests Dean.
Sam and Dean agree to both work on getting and killing Abaddon.