His presence is marked by icy mirrors and flickering lights.
In the penultimate episode of Season 7, Sam and Dean Winchester race to assemble a powerful weapon to take down Dick Roman and the Leviathans. Following instructions from the Word of God tablet, they must combine the bone of a righteous human with the blood of three "fallen" beings: a fallen angel, the King of Hell, and an Alpha monster. The Quest for the Alpha's Blood [S7E22] There Will Be Blood
While the brothers are away, Bobby’s ghost continues to struggle with his mounting rage. His presence is marked by icy mirrors and flickering lights
Kevin Tran remains a prisoner, forced to translate the Word of God under the threat of his mother’s life. The Quest for the Alpha's Blood While the
Sam and Dean discover that the Leviathans are poisoning the human food supply with a corn syrup additive. This additive makes humans lethargic and "tasty" for Leviathans but is lethal to other monsters, such as vampires, who feed on them.
The Leviathan Edgar arrives to kill the Alpha and "purge" the vampire race. After a tense struggle, Sam decapitates Edgar with the brothers' new "vamptonite"—blood taken from a corn-syrup-dazed human—giving the Alpha a change of heart. Grateful but still hostile, the Alpha hands over his blood and releases a captive boy, Allan, to the Winchesters. Bobby’s Descent