While Sam and Dean have two of the three blood samples, they discover Bobby has vanished, and their only remaining ally, Crowley , is now in the enemy's hands.
While the brothers are away, Bobby’s ghost continues to struggle with his mounting rage. [S7E22] There Will Be Blood
Kevin Tran remains a prisoner, forced to translate the Word of God under the threat of his mother’s life. While Sam and Dean have two of the
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 In the penultimate episode of Season 7, Sam
Dick Roman summons Crowley into a devil’s trap to prevent him from helping the Winchesters.
With Castiel’s blood already secured, the brothers turn to Crowley. He agrees to help but demands they find the first, as his own blood is a "last resort" that could be used against him.
The episode ends on a grim cliffhanger that leaves the Winchesters nearly alone: