Sam cuts off his phone after listening to the message Dean left him. How did he get here? How did he let himself turn into this... this monster? He can't hide from himself anymore that his brother's right about that. But Sam's so close to the finish line now, so close to ending the race toward the apocalypse, how can he just stop. This is it, he thinks, this is the last time I drink demon blood, the last time I use this dark power inside me...