Sam and Dean's grandfather, Henry Winchester, arrives by time travel, claiming that he has something to protect from an Abaddon that is hot on his trail.
While searching for Kevin, again, Charlie joins up with Sam and Dean as they track down a creature that's been liquefying its victims. Plus, a new side of Charlie is revealed.
Sam and Dean search for the Word's author, Metatron. Castiel tries to protect the angel tablet. Kevin tries to solve the third trial under Crowley's supervision.
Sam and Dean try to figure out how to cure a demon. Crowley starts killing victims that Sam and Dean have saved from previous jobs. Castiel and Metatron begin the trials to close the gates to Heaven.
Sam and Dean capture Crowley to finish the trials and close the gates of Hell. Castiel and Metatron continue the trials to close the gates of Heaven. Sam is left with a huge decision.
Dean and Castiel team up to find a Rit Zien, an angel healer, who is easing peoples' suffering by killing them. Sam and Kevin ask Crowley for help in finding a way to open the gates to Heaven.
Sheriff Mills calls Sam and Dean for help with multiple disappearances in the town. Discovering all four victims belonged to the same church chastity group, Sam and Dean decide to infiltrate by joining the group themselves.