Supernatural became the longest consecutive United States science fiction television series with 218 episodes. This surpasses the previous record holder, Smallville (2001), which has 217 episodes. It would go on to have 327 episodes overall.
Crowley mentions that the Forbidden Fruit from the Garden of Eden was not an apple but a quince. The quince is one of the fruits that ancient sources have theorized to be the Fruit, since it is never actually identified in Genesis.
The Latin incantation that Dean uses to summon Death is: "TE NUNC INVOCO, MORTEM. TE IN MEA POTESTATE DEFIXI. NUNC ET IN AETERNUM." Which loose translated means: "I invoke you now Death. You are in my control, now and forever."
The Latin phrase Death says: "CREATIO EX NIHILO" translates to: "creation from nothing."
The title refers to the passage in the bible when God questions Cain after he has killed his younger brother Abel.
"Then the Lord said to Cain, 'where is your brother Abel?' 'I don't know,' he replied. 'Am I my brother's keeper?'"