While investigating a series of murders, Dean is infected by the creature dubbed the "Khan Worm" which forces him to kill Gwen.

In "Metamorphosis", Sam says: "Listen to me, you've got this dark pit inside you. I know. Believe me, I know. But that doesn't mean you have to fall into it."

Dean Winchester is NOT one of the "Special Children," chosen by the Yellow-Eyed Demon to take part in the Apocalypse.

Dick's package arrived from in America via New York where the Leviathan Agent Valente expedited it through customs. It then flew to Downey airport Chicago on one of Donald trump's private jets. This information is obtained when Charlie Bradbury hacks Dick's e-mails.

Rowena, portrayed by Ruth Connell, is a powerful witch introduced in the tenth season. She is eventually revealed to be Crowley's mother.

The biggest Supernatural romance may be Dean Winchester and his love of pie! Unfortunately for Dean, it has become a running gag on the show that he rarely gets to eat his favorite dessert.

Lucifer was finally freed and allowed to roam the Earth when the final seal (the death of Lilith) was broken by Sam. Freed from his cage, he set out to bring about the Apocalypse and cleanse the Earth of human beings.

Pamela Barnes is a skilled psychic who helps Bobby discover who or what pulled Dean out of Hell. She holds a seance and learns it was a being named Castiel, but when she gets a glimpse of the angel, her eyes are burnt out and she becomes permanently blind.

Lilith was the first demon Lucifer created, as well as being the final seal of the 66 Seals that had to be broken for him to be freed from his cage.

Tessa is a reaper who guides the deceased to the afterlife. When Dean goes into a coma following a car accident in which he is critically wounded, she poses as another coma patient and tries to convince him to "move on", but Azazel intervenes and restores Dean to life.